Smyth Busters: Are Piston-Operated AR-15s Better?

Brownells Gun Techs Steve Ostrem and ‪@CalebSavant‬ are back to take on the myth that piston-operated AR-15s are better / more reliable than standard direct-impingement ARs. As the guys demonstrated in an earlier Smyth Busters episode ("Is the AR-15 Really Piston Operated?"), the AR-15 is not actually a pure direct impingement rifle but a kind of hybrid, with the bolt operating like a piston. In this episode, "direct-impingement" means an AR-15 with the traditional gas tube above the barrel.
Caleb points out there have been a lot of attempts at piston-driven AR-15s, some of which were terrible. The Heckler & Koch HK416 was purpose-designed to be piston-operated, and it works VERY well, as does the Brownells BRN-4. Any good piston-operated AR-15 style rifle will be more expensive than a direct impingement one because it just costs more to manufacture the additional moving parts. And it is heavier.
So what's the benefit of a piston? A piston AR runs CLEANER and COOLER. It doesn't blast hot gas back into the receiver and bolt-carrier group, which increases the gun's longevity. This is a huge benefit in full-auto fire, too. A direct impingement AR-15 runs hotter and dirtier, but the rifle is lighter. And after 60+ years of development and refinement, it is also very reliable.
What about those "plug-n-play" piston conversion kits? They involve engineering compromises that cause "bolt tilt." In direct-impingement, the gas pushes on the bolt in line with the bore so the bolt and carrier move in a straight line. With a piston conversion, the force hits a lug on top of the carrier where the gas key would be. This force is off-center, causing the carrier to tip down at the rear, tilting the bolt upward. The result is accelerated bolt wear and malfunctions. Purpose-built piston guns like the HK416, BRN-4, and AK series are designed to keep the piston force properly centered.
So the myth is BUSTED. A piston AR is not always better than a direct impingement AR-15. Direct impingement is more reliable than a piston conversion kit. But a purposed-designed piston system is more reliable than either of them. A direct impingement AR-15 is the most cost-effective option for sport shooters. But if you have the spondulicks, try the HK416 / BRN-4 route.

[@CalebSavant]

A good DI system is better than a converted piston system! Also, it's January! That means it's time to vote for me in this years Gundie Awards as "Most Dapper"!

[@brownells]

www.thegundies.com/creator/caleb-savant

[@03redrubi]

The Dapper DOM!

[@jwilsonhandmadeknives2760]

It's a tough call between Caleb's hair and James Reeves' short shorts.... but I'm going to have to throw my significant weight behind Caleb. And no, I don't mean it like that. I'm not James Reeves, for pete sakes.

[@user-mj1vb8jr6j]

@@jwilsonhandmadeknives2760better watch out bud. Steve hears you talking about his son Kaleb he’s likely to take you out behind the gym and have a nice lil conversation with yuns.

[@Paladin1873]

Caleb is single-handedly bringing back that retro 1963 look.

[@junkdubious]

The older guy is low-key a sage, asking the right questions.

[@machinemaker2248]

They almost always are.

[@LOOoZZzERr]

About smacked my knee when he said bolt tilt and the old guy with no pause 100 percent seriously said "I knew we were gonna come around to that" when I've never heard the term once. What a clear explanation though

[@bills6946]

Good cop, bad cop syndrome

[@RoachSurfs]

​@@LOOoZZzERrCarrier tilt?

[@leroybishop2245]

I’m sure many viewers would enjoy a comparison video regarding which hair gel works the best for range time versus in studio use.

[@woohoo2you966]

I just want to know if the same gel is used during a category 1 through 5 hurricane.

[@STEVEARABIA1]

Poor Caleb takes a lot of heat.

[@brownells]

The answer is the same regardless, Caleb has a custom line made just for that immaculate hair. loxandcompany.com/baron-balm-hair-pomade/

[@fire_tower]

Canonically Caleb has a whole can of Crisco ® in his hair.

[@lescoburandun1457]

I heard he found a life hack and uses loc tite

[@russbetts1467]

Piston Guns. I served in the British Army during the 1970's. My Service Rifle was the L1A1 Imperial version of the Metric FN FAL. That used a piston - we called it a Tappet - to unlock the bolt. That ran very cleanly and the only part which gathered Carbon, was the head of the piston and the Isolation Plug. Spent gasses came out of two holes on either side of the Gas Regulator, which was barely an Inch behind the bleed hole from the barrel. The Bolt and firing mechanism remained cool, even under extended firing conditions on a hot day. Gloves were never needed to prevent burnt hands. Cook-offs from a hot breech were unknown. Cleaning in the field was simple, even under Combat Conditions. From my perspective, the HK416 system appears to be overly complicated, but having never handled or fired one, I have no idea how good or bad it is. From my observations, most modern European Military Rifles are Piston driven and very reliable and only America is using Direct Impingement personal weapons. Go figure.

[@Six_One_Six]

We've got it all...DI, Piston, Blowback, roller delayed blowback, Short stroke, long stroke....variety is good. Aside from full auto stuff, we as citizens can have better parts than the military does in some cases. We're running the same chrome lined barrels, but all of our high speed parts can be made from more wear resistant steel and can have slicker and more wear resistant coatings. We also have a variety of lubes available.....even when extremely dirty after months of use, my carriers slide back and forth like they're on ball bearings.

[@Roli238]

​@@Six_One_Six question for y'all - what cleaner / lubricants are your first choices.? I like FP10 but my days of working the (gun) counter or range days are behind me so I'm not up to speed anymore. I have FP10 so old I think it's turning back into a dinosaur ffs. Stay frosty y'all

[@MrJbrew69]

Man, I have a Adams Arms with probably 2500 rds through it, cleaned it barely 3x, not one issue.

[@freedomlineman3105]

Please… name the poor piston AR system manufacturers. Education is key

[@Ratkill9000]

Anderson comes to mind

[@ryanthorne5432]

Most of the poor piston AR makers are not making piston ARs anymore.

[@joeytomato]

@@Ratkill9000 Anderson doesn't, make one... Never did.

[@thickoc4539]

@@joeytomato There's! Something, Onthewing

[@roul3688]

HK, Barrett, Colt (at one time), PWS, Adams…

[@dogsnmotorcycles]

I've used 2 different piston conversions over several years with no failures or apparent unusual wear. Adams Arms and Bushmaster kits. They weren't cheap and made my guns heavier, but they have worked perfectly over 10 - 15 years. I also have a DI upper that works pretty well too.

[@Papa_Datat_Foxtrot]

Plus Adams Arms had phenomenal customer service. I sent my AA Upper back with a lower I built myself (per their request). They worked on my lower free of charge to make sure it was compatible with my upper. All with shipping paid both ways.

[@ryanjofre]

Nice. Bushmaster is coming back!!!!

[@malakaichanel3321]

My Double Star CAR-15 with the Adams Arms conversion has never failed me. As a range toy with a few 1000 rounds, no issues, no bolt tilt wear. 🤷

[@satrapish]

I used the HK 416 in the French army, it runs great, even after thousands and thousands of rounds, they still work excellent. the piston gas should be cleaned more thoroughly. But yes it is more expensive. Great video guys. Godspeed

[@sonatine3266]

There is a reason why the HK416 is used by almost every SOF unit and several armed forces in the world.

[@jimmyrecard6021]

allegedly the gun that killed Bin Laden.

[@9770G]

@@sonatine3266 MAC took a stock BCM upper and ran it for 8k rounds with cleaning or lubing it once and it ran fine .

[@JJGuccione]

@@9770G I don't believe he's an honest man. I appreciate Mac's VDOs but he's like Bill Geissele, profit driven and downright avaricious.

[@rustynail246]

Then why did the French army get their asses kicked in all major battles?

[@qedsteve]

"Back in the day" I owned an AR-180 and always thought that a properly-designed piston-type just made good sense. (Should never have sold it)

[@czwarlord9243]

Your in luck. Brownells brought back the ar-180. It’s called the brn-180. They have also made some reliability improvements to it. From what I have seen it runs like a sewing machine.

[@BOB-wx3fq]

The ar18 is grossly underrated and I'm so glad they are making a comeback

[@user-vh9hs4qe7r]

If the piston ones were so good, our military would use them. Don’t feel sad that you got rid of yours. Be glad.

[@chrisblack2330]

​@user-vh9hs4qe7r weird way of showing you know nothing about the military 😂😂😂ask any of us veterans and we're all running piston systems because my personal shit is better than military grade

[@VeritasEtAequitas]

​@@user-vh9hs4qe7r lol. The military uses lowest bid contractors. Military standards are lowest common denominator.

[@tonybailey89]

I absolutely love taking out the BCG on my POF P415 Edge 16.5 that's a short stroke piston system and simply wiping it and the upper receiver down...clean up is literally a fraction of the time...piston guns all day for me

[@lukelacross190]

Same, love my LWRC M6 IC SPR, but about to buy a P415 edge upper for my night rifle build

[@tonybailey89]

@@lukelacross190 LWRC is among the cream of the crop! If you buy a POF P415 it won't be your last lol, I'm hooked and will be picking up a POF Revolution 308 12.5 from them as well! Runs smooth as butter, tolerances are tight as you can ask for, and build quality is absolutely flawless

[@chadedwards7072]

I was sold on POF after watching them run 10K rounds through one with no mechanical issues.

[@tonybailey89]

@@chadedwards7072 this POF P415 Edge 5.56 is built like a sexy tank I'm absolutely in love with it!

[@jameskuhn4020]

I hate cleaning DI ARs! It's why I had an old Bushmaster converted to Gas Piston Operation and the reason I purchased a complete PWS rifle.

[@robertducharme1424]

I run a LWRC as my rifle. I think it is the best set up out there. Lighter weight than a HK. I also run Adams Arms pistons on my full autos. They take the abuse of being ran all week end long with no issues year after year.

[@gillbrown8520]

I'm with you. I've been running my LWRC IC for 10 years, on my second barrel. Never had an issue, I love it. But at the same time, I have ner had issues with my DI guns either. But for a go to war rifle, give me a piston.

[@davidkiser5250]

Love these videos/commentaries! I feel this is the best and simplest explanation and stating of the pros and cons of both I have ever seen. Thanks Brownells; great job.

[@solomonsgtjustinl9724]

I have a PWS long stroke piston system, have had it for at least 15 years now, and love it.

[@ColeMD17]

One of the most solid manufacturers that almost no one ever talks about

[@JohnLocke1776]

100% bros. How this company isn't more popular is kinda crazy

[@MadMetalShop]

Have had one of their OG mod 0's for the last 12 years. Still my best AR. Mk114 when it was offered in FDE and the quad rails.

[@Lynviking]

I have two and PWS is hands down the best

[@thehebrewyisraeliteinstitu1868]

PWS RIFLE MK114 MOD 1-M FDE Specs: SKU: 18-M114RA1B UPC: 811154030252 Operating System: PWS Long Stroke Piston System, 3 setting Adjustable Gas Regulator Caliber: .223 Wylde Barrel Length: 14.5” Gas System Length: Mid-Length Barrel Twist Rate: 1:8 Muzzle Velocity: 2921 fps 2” Triade Series SERIES FSC556 GEN.1 PWS FSC 556 (pinned & welded) Upper Receiver: PWS Proprietary Piston Upper, T6 7075 Forged, Anodized Handguard: PWS M-Lok™ 13.624” Handguard (1.7” width, 2.25” height) Charging Handle: Radian Raptor™ Ambidextrous Charging Handle Lower Receiver: PWS MK1 MOD 1-M Multi-Caliber Lower, T6 7075 Forged, Anodized, AR-15 Compatible Trigger: Mil-Spec Enhanced, PTFE Coated. Trigger Pull Weight: 5.5 - 6.5 lbs. Buffer Tube: PWS Enhanced Buffer Tube with ratchet lock castle nut and end plate set with built-in QD mount Buffer: PWS Enhanced H2 Steel Body Buffer Furniture: Bravo Company USA® Buttstock and Pistol Grip FDE COLOR

[@ssnerd583]

I have a Wolf A1 piston upper(that is directly from the Taiwanese T91) that will work on any Mil-spec AR15 lower. That upper has had at least 25k rounds through it from junk steel case stuff to Mk318 mod0 through it and its never even blinked.....its chrome lined barrel and chromed chamber and its accurate and works great.....LOVE it. My best 16" upper.

[@brandonf3727]

Thanks for comment, I was looking into them but knew nothing and hard to find anything about them

[@9770G]

Cool but u can buy a aero upper for $400 that will survive 25k rounds for sure too…

[@ssnerd583]

@@brandonf3727 ...its my fav 16" upper, really. its very accurate with most all ammo I have used but the mk318 is very tight grouping.

[@ssnerd583]

HAHAHAHA.....its not an original piston design, it's a 'kit' and it wont last as long as the A1 which was designed from the git go as a piston upper and has none of the fatal flaws of the 'kit' piston uppers like the Aero@@9770G

[@lukelacross190]

I think one of the biggest advantages to going piston is if you’re planning on shooting suppressed. LWRC and POF are superb in this matter that you don’t get gas in your face like a di with the adjustable gas blocks they offer for this.

[@JJGuccione]

So is PWS -

[@tenko8519]

I must agree POF is superb… POF fanboy here, love the brand/company!

[@TheGunNerd]

I'm used to shooting lots of rounds out of an overgassed system, I don't mind di with a can

[@binyamj]

Pistons do not cut down on gas. Tavors are a prime example. They will give you ten times as much gas in the face as a DI rifle. AK’s as well.

[@JJGuccione]

@@binyamj • You're drinking bad Kool-Aid.

[@hulldefilade4897]

All excellent point made. Can't argue against any of them. I've got an Adam's arms piston driven upper. I've run that upper for almost a decade now, lost a round count on it a long time ago. Still runs great and I don't see any abnormal wear. Each system has its pros and cons but I've been pleased with mine.

[@zsb23]

A superlative Arms piston retrofit kit equipped with a roller style cam pin (POF) and utilizing an anti tilt buffer tube has been very reliable for me over approximately 3000 rounds, albeit only a sample size of one. The weight of a SA kit is very minimally heavier than a DI system and it works with a much wider array of HG's than most other retrofit piston systems. It's at least a good affordable option for someone set on running a piston AR.

[@zsb23]

@@charlesmciver897 I run the POF roller pins on all of my AR's. Have also had a POF piston gun that was great despite it's weight, but the SA piston kit is more simple than the POF and much lighter. If pistons interest you, I'd definitely recommend it.

[@alouiciousjackson5812]

Exactly. This is also my preferred setup for a conversion.

[@asymsolutions]

@@alouiciousjackson5812 It's a shitty setup, had it, then went to an external spring design ala H&K and AA. Reason why? If you shoot suppressed, binary, or registered lower, the heat is past what that repurposed mag catch spring can handle and it will embed itself into the rod. It's a range toy system, you only ever expose springs to a constant heat/cool cycle when you can't avoid it due to changing the metallurgy. A short stroke system does not require that sacrifice. I would rather someone stick to the "DI" set up of the AR15 than convert to that system. The only benefit the SA system gives is "cleanliness" which is a non issue for the AR15 system if you actually educate yourself on it. So the advantages: rapid fire heat transfer to the receiver and decibel reduction under suppression (especially to the operator) of a piston system is completely negated under the SA design. Go back to DI, or get a real piston system. AA is the lowest I'd go in quality, and that's because it's the only semi-decent external out there that tries to make their system work with the "roll your own" crowd.

[@alouiciousjackson5812]

@@asymsolutions I've noticed that the spring does need to be changed more often than I'd hoped. Supposedly you can run it without the spring but I've never tried. But people complain about the AA systems also. I agree that a good DI is probably best.

[@alouiciousjackson5812]

@@asymsolutions Thanks for making me think about this. I'll be removing the spring from mine. I just checked SA's website and here's what they say about it: NOTE: Not required to safely operate the piston system. We do not use these springs on our personal builds, military or law enforcement builds. We have done a 10,000 round torture test without the op rod spring resulting in zero failures. This is just a mag release spring that helps eliminate the small amount of rattle the op rod has inside the gas block. This spring will fail at a certain point and will need to be replaced. You should inspect your spring after each use if you choose to use it.

[@robertcolpitts4534]

I have the excellent SR-556 piston rifles from Ruger (now discontinued). Mine just runs and runs with no excessive wear from carrier tilt, not bolt tilt as mentioned in the video. Ruger had a problem initially with tilt but cured it by changing the configuration of the rear pads on the Bolt Carrier. After that, no problems. And it is plenty accurate with M-193 ball. It does like the 62-grain HPBT, too. Before someone mentions it, yes it is heavier than a DI gun owing to the heavy barrel and piston parts, but not that much heavier.

[@ahndeux]

My SR-556 is the favorite AR15 even though I have several Colts. That gun is a beast and will run and run. I put at least 2000+ rounds through it over the years. There something nice about not having a gun fart in your face every time you pull a trigger.

[@carlleber3339]

@@ahndeux - Same experience w/ my SR-556 and being a lefty - it's nice not to breathe all the gases coming from the upper receiver

[@ahndeux]

@@carlleber3339 Yup. It helps if I clean the bolt out once in a while, but have been running it flawlessly without a lot of cleaning. I love that SR-556.

[@scottwilson1258]

I have an Adams Arms Upper for what is my Range/Home gun and have Found it Very Clean and Very Dependable. I don't consider my purpose to be used in Battle,Just wanted a Fun Rifle and it has been Flawless so Far!

[@jamesbeason9256]

I use my Fostech lower in an Adams. Can't hit much, but it runs like Forrest and stays clean doing it

[@ouruiz]

I remember back in the early mid 2000's the talk was "Is DI systems more reliable than a Piston system?" or vice a versa. I remember reading forums and watching KZbin videos saying that "This system is more reliable than that one". I am glad that Brownells finally can put that argument to rest as well.👍

[@stantonsellers2137]

I love how the more senior host looks unimpressed and the younger host looks to him while speaking for approval (joking) great pair love the content! Keep it coming

[@southernexposure6855]

Love my PWS 11.85”. Runs much cleaner especially suppressed. Easy to clean and never malfunctions. Only downside is that it is noticeably heavier out front than a DI. Recoil impulse is different but fine once you get used to it.

[@forkthepork]

I wonder if they could make that out of titanium or some other material to save weight?

[@southernexposure6855]

@@forkthepork that would be a great option cause she thiccc. Needs to go on a diet for sure

[@JohnLocke1776]

PWS is not noticeably heavier. I have the mk116 mod 2 and it's less than 7 l.b.s. I agree on the recoil impulse thing. I actually like it tho. my favorite AR 15 actually. It's my go-to rifle for shtf, grabbed it during the 2020 riots when I lived in L.A.

[@SPIRIT-117]

​@@JohnLocke1776pws is noticeably heavier in some cases. You mentioned you have the Mod2, which was pws attempt to lighten that thing up as much as possible and it still weighs as much as a typical DI gun that wasn't build with lightweight in mind. I have a Mk116 Mod1M (the one that was designed for duty use and not lightweight) and it's absolutely noticeably heavier than any regular 16 inch DI gun. Is it a huge problem? No not really. But it is noticeably heavier for sure, and if that weight difference is a concern to you, either need a PWS Mod2 (which are more expensive) or you need a DI gun.

[@Borderline5440]

Glad to see someone mention PWS; I just got my Mk116 Mod 1 last week and love it already.

[@_datapoint]

It's always interesting hearing from you two. Caleb's knowledge is apparent. But Steve's clarifying statements are invaluable.

[@m118lr]

…ha ha ha

[@murphymmc]

Great explanation. Understanding the physics of how these systems work or don't work is key, for most of us the "almost a DI" is fine, the aftermarket upgrades to piston have a poor track record, now we see clearly why.

[@shaunspies1108]

Hello from a Boer, and new subscriber to your show, in South Africa. Great show! Personally, I prefer the Piston, as we use it on our R4 rifles, based on the Galil. Never had a problem with it since 1986. It is extremely reliable, no matter how many rounds you put through it, before cleaning it. Happy Christmas, and may your 2024 be truly blessed.

[@JLR77]

The PWS piston system is solid! I LOVE mine. Never had a single issue and I’ve ran mine for years!

[@victoroneill7924]

A good friend quit school and joined the Army when he was 17 and went straight to Viet Nam after training. He survived 2 back to back tours as a LRP (Long Range Patrol) back when the AR-15 was very prone to jamming. He became a fanatic about keeping his AR-15 clean. When they went to the field they carried as much ammo as they could but no food or water. He saw a lot of action and was never wounded but Agent Orange ruined his health.

[@quangduongang6230]

Yeah that chemical was really nasty. I hope his children wasn't affected by it though

[@sydecarnutz972]

I'm sorry to hear they issued him a AR15 vice a M16. Semi auto only must have put him in a difficult position. I've lost a couple friends to the effects of agent orange. Very sorry for your friend's sacrifice.

[@neiljasonvillanueva1864]

@@sydecarnutz972 Armalite Rifle 15 were never issued as semi auto in Vietnam. Only they didnt have forward assist and chromed chamber/barrel until m16A1s arrived.

[@dittman2564]

From what I remember, the military ammunition used the wrong powder in the early stages of using the Colt in Vietnam. It was specified to use ball type powder I believe, and the military used stick type powder, which was prone to fouling the gas system/action especially in damp climates.

[@zoltancsikos5604]

​@@dittman2564There seems to be a trend these days where everybody acts like the ammunition is to blame for everything... Yeah, everybody from the inception of the AR to present day has been doomed by cheeky propellant in a bunch of different countries.

[@josephzawacki5208]

Years ago, I purchased a CMMG piston system from Brownells. I installed it on 11.5 SBR Bushmaster with a LaRue handguard. I drilled and pined the gas block and had to mill the inside of the LaRue so it could fit. I put tens of thousands of rounds through it at action Rifle and three-gun matches. I did purchase Two more of the CMMG systems from Brownells and have had no issue with them (lower round count). I notice a different recoil impulse to add to the differences. My two cents. Keep up the interesting videos.

[@MyFlexinIsAProblem]

I’ve owned about a dozen direct impingement AR’s they’ve been great. In the past year I’ve picked up a Sig 516 upper and BRN4 HK 416 clone upper. Don’t have a ton of rounds through them yet but they are very fun to shoot. A lot heavier like they mentioned in the video but it doesn’t bother me. DI AR’s were getting kind of boring. I also own several AK’s It’s cool to own all of the operating systems.

[@danemaui8259]

I have a Ruger SR 556. The handle/grip was switched out along with a couple of other minor things cosmetically by The collector that owned it before me. All the actual moving parts the original. You can tell when you hold the gun that it's quality. I have fired quite a few brass and steelcased out of it. Also can hit with the magnifier perfectly at 100 yards out. Never had any issues. It's my baby I truly love it. The amount of ammo that I would have to put through this thing in order for it to get dirty..... You're talking thousands and thousands of rounds. And even if it starts to malfunction you just crank up the piston. I never had to though and I'm sure I never will. They are the perfect zombie apocalypse rifle/Chinese invasion rifle. Good video thanks guys

[@CJLiveFromTheOutdoors]

Another great video! Thanks guys!

[@darthhodges]

If you're someone who puts lots of value in mud tests and the like InRangeTV found that the gas venting from the bolt carrier in the "pseudo" DI AR15 was an advantage. It tended to blow the mud, etc. from an open ejection port reducing the chance of stuff falling into it while the weapon cycled. They showed slow motion footage clearly indicating that this was the case. By comparison both piston ARs and other piston guns often had problems with mud falling in after the bolt barrier moved back. A niche concern but there are those who think it's significant.

[@HalIOfFamer]

Imo its pretty significant for military use.

[@Arkrilok]

They also put a rock inside the chamber of the piston gun and said it was somehow a failing that it wouldn’t go into battery.

[@michaelolexa4147]

@@HalIOfFamer i like Inrange tv, but Karl is the weak link, if he does not like a brand or gun, it will FAIL!!! Real tests are UNBIASED and realistic. and don't have a Karl

[@doncarr9860]

There is a video somewhere on how well the piston AR doesn't like the mud test. I've seen it.

[@doncarr9860]

@@michaelolexa4147 I don't agree.

[@GeneD283]

I have the LWRC IC-SPR which has the piston operating system. You didn't mention it in your discussion but I can confirm it has a sharper recoil impulse than the Colt AR15 I had years ago. Mine shoots sub MOA so I wouldn't argue that the DI rifles are more accurate

[@Semi-J]

Hydraulic buffer H2, you would love it

[@warrenlovell3919]

Also have LWRC. No issues in thousands of rounds fired using 5.56 Lake City. Gas impingement are definitely dirtier

[@wayneeck9805]

I just enjoy listening to you two! Keep up the good work!

[@francistrinh3957]

Steve, I love watching your shows and thank you so much from the bottom of my heart. To answer one of your questions, DI gas vs piston driven, I must say the piston driven is much much cleaner if the owner of the rifle is a shooter who practices every week. I am an old timer and believing track records like you. I can't fully trust the piston gun yet, at least not every brand. It is not fair to use one single HK 416 to compare with the entire DI gas system industry to prove the system's reliability. I built my with the Adams Arms system and a FN barrel because of the high round count barrel wear. So far, I like mine. I just hope that one day all the piston systems will be just reliable as the DI gas. BTW, I cannot tell you how much cleaning time I have saved with my piston rifle. Just dry brush it, run a couple wet chemical patches through it, and I am done and ready for the next practice day.

[@user-do1fq8oy9c]

I have an L.W.R.C.I. REPR .308, runs fine. I have a Sig 516, runs fine. I have a 7.62x39 AR built with an Adams Arms piston (even tho AA doesn't list x39 as a cartridge their system will run) runs fine. These three systems work well and I see no weird wear. I have also never replaced the extractor/ejector springs either. Kalebs point about bolt tilt was relevant until more "perfecting" was also put into piston systems. Also, the FAL has the exact same strike on top of carrier AND... it's location is the very front of the carrier. No problems with the design. Now before the jury writes me off as a "D.I." hater, know I have rifles and carbines from A1 to A4. I would also like to know who made these bad conversions. Uncle Gene made his rifle initially as a piston. It was $$ savings that McNamara demanded (among other stupid changes) that gave us the rifle as we know it.

[@JohnBrowningsGhost]

An FALs strike on its carrier is irrelevant, the FAL bolt carrier rides on rails, the whole reason why the AR 15 piston rifles had issues with carrier tilt initially was the ar bolt has no guide or rail to ride on.

[@user-do1fq8oy9c]

@John Brownings Ghost so you are saying a tube inside a tube is not as good a couple small rails? The idea here is the leverage (the distance between the bore center and the strike surface) as well as the fact that surface is about a third the way back from the bolt face, this creates a tilting effect. If you look, the FAL has a much longer lever, and it's located at the very front of the carrier. The FALS bearing surface (those two tiny rails) is nowhere near the surface area of the tube in tube design of the AR. Not to mention the FAL carrier is shorter that the AR carrier. Common sense should tell you the FAL should be terrible (if Kalebs theory is correct), and have a short service life.

[@daemonescarnifex]

I built a 12.5", midlength gas, DI upper in 7.62x39 as an apples to apples comparison to my PWS MK111 in 7.62x39. With each of them tuned perfectly thee PWS upper shoots much smoother and is much cleaner but it is also much heavier. So I have the PWS set up for home defense and the DI setup for hunting to cut some of the weight I'm carrying around.

[@hawkgrunt4182]

Thanks Gentlemen, awesome segment!

[@kvnkaveman]

I have an Adams Arms piston system and it is fantastic. I have never had a failure in over 2000 rounds.

[@sahliwill]

I have a SIG 516 Gen II short-stroke piston gun that runs perfectly. Having a big quadrail handguard makes it even heavier than the H & K 416. I agree short-stroke piston guns aren't necessarily better than direct impingement guns in all cases, but they have some distinct advantages.

[@blckandwhtknight]

Decent overview. Should have mentioned suppressors and accuracy. Most shooters won't realize the difference in accuracy for casual use but high-end accuracy is dominated by DI. On the flip side, suppressing a DI gun is a pain, and the advantage goes heavily to the piston.

[@JamesS.254]

Shooting suppressed was my reason for getting my piston upper. Gas in the face even with gas buster charging handles was no fun. I do however run adjustable gas blocks on two other AR’s and they have worked great for reducing/eliminating gas in my face.

[@Jammaster1972]

My thoughts exactly. Could not have said it better. Big oversight on the content of this video.

[@rustys.1070]

why is the 417 more accurate than the sr-25 then???

[@jordandebuck9903]

Why is it that the high end level of accurqcy is dominated by di? Is it a combination of reduced recoil and recoil inline the bore or is it something like improvement on barrel harmonics with less parts to be moving and parts moving further from the barrel?

[@blckandwhtknight]

@@jordandebuck9903 yes, all the above, the big one is harmonics. For top accuracy you want the barrel as free floated as possible.

[@ChristopherSmithWHAM]

All but one of my 7 AR uppers are DI, and I’m quite happy with them. I built one pretty nice piston upper, using a mid-length Adams Arms piston kit, shortly after I bought my first suppressor. My theory was that the gun would run a lot cleaner while suppressed if I had a piston upper on it. (This was prior to the release of the OSS/Huxwrks "flow-through" baffle designs.) In actual experience, it didn’t make that much of a difference. The inside of the receiver still got pretty dirty, and a LOT of gas blowback down the barrel (thanks to the suppressor design) also fouled up any remaining ammo still in the mag-coating the cases with a carbon deposit that seemed like it might threaten reliable feeding if it got too bad. Also, the gas venting out of the piston coated the area forward of the gas-block with a fine layer of carbon. My other 2 piston guns-an AK and a SCAR-do not suffer this problem to the same degree. All of that said, I maintain that the "DI" system *IS* a piston system. It’s just that the piston is incorporated into the BCG and is in-line with the bore-behind the chamber rather than in front of it. I’m probably going to swap that Adams Arms piston kit for a standard DI system and bolt carrier.

[@detritus23]

Two features a short stroke piston have over hybrid DI are adjustability of the gas system (in some.instances) and no gas venting at the ejection port, particularly when shooting suppressed. As a lefty, not getting gas in the face is always appreciated.

[@BlazingGunner]

I love my Sig 516 I have many other piston guns CZ Bren2, Scar17S, Styer AUG and my Desert Eagle 50 AE to name a few. Piston guns can be suppressed with less blow back to your face.

[@johnhatchel9681]

That Sig 516 is underrated in my opinion.

[@michaelolexa4147]

you notice they only talked about AR Conversion's, none of the purpose-built rifles. if they had, the only thing they could say was the AR is CHEAPER.

[@ahndeux]

I love my Ruger SR-556. It's a beast. I ran at least 2000+ rounds through it over the years. The only thing that ever failed was the retaining pin on the buffer weight.

[@MW-jj1rn]

Excellent information, well done.

[@emusoda]

These guys should check out the PWS piston system. Long stroke just like the AK

[@michaelolexa4147]

Why, then they would have to add rifles like the Scar, AK, CZ Bren, and then their whole store will fall apart except that AR is cheaper to build... you see they only talked about AR Conversion

[@emusoda]

@@michaelolexa4147 because the pws is an AR and they are talking about piston ARs.

[@Jrhoney]

@@emusoda PWS rifles are AR style rofles with a long stroke gas piston, like the AK.

[@emusoda]

@@Jrhoney I believe you replied to the wrong person

[@tedhodge4830]

It's hard to check out the PWS piston system when they're always sold out. My understanding is that Brownells may have actually worked with PWS to make the BRN-180. What they need to do is work with them to get some PWS rifles on their storefront because that's what I really want.

[@robertpettus6037]

My issue with external piston system is the stresses that are applied to back of the ar15 locking lugs being snatched back against the barrel extension lugs during bolt unlock. The internal piston bolt doesn't see this issue as the gas pressurizes the gas expansion chamber opposed to the bolt carrier being forced to unlock the bolt by being hit. Hope I was able to convey my issue properly here.

[@robertpettus6037]

@@charlesmciver897 no respect due lol. You stated top tier addressed this issue of bolt and barrel locking lugs... because it needed addressing. LMT addressed their bolts and carriers and others only added bolt springs... I wouldn't trust a bolt spring but yes, LMT figured it out.

[@snowflakemelter1172]

You're right, the AR was designed for the gas tube system and adding a piston is only ever a bodge, a piston striking the gas key to operate it was never designed for.

[@gunfisher4661]

Basically I think it boils down to what pistons ,carburetor and exhaust do you want on your hot rod ,what is it going to take for you to have that confident cool feeling. The two subjects have a lot in common don`t they.

[@jjjr.1186]

Ar15 isn't internal piston. The piston keeps the gun locked under high pressure. On a piston the gas hits a piston that actuates the carrier. On impingement the gas actuates the carrier. The ar15 is the latter.

[@robertpettus6037]

@@jjjr.1186 there's literally piston rings on the bolt. The ar15 is not what was or is known as direct impingement, it is only colloquially known as direct impingement due to people not knowing the difference. The gas system unlocks the bolt by utilizing expanding gases from the fired round to push the bolt forward against the barrel and the carrier back against the buffer and springs. When the carrier travels far enough the cam pin, utilizing the cam track cut out of the carrier which is moving rearward, rotates and spins the bolt unlocking it. Once it has been unlocked the remaining pressure in the system, mostly in the barrel, continues to force the bcg back until the action springs can no longer be overcome or bottom out. Then those springs, acting on the carrier through the buffer mass, close the action up by forcing the bcg back into position and the process can start over. If everything works well, the fired brass was ejected and a new cartridge was loaded into the chamber and bolt locked under spring function.

[@AngeLa-du3gw]

Love my HK416 and my newly built BRN4 great video as always

[@thelastjohnwayne]

Caleb Thank you for this video.. This would explain why the Navy Seals at times use H&K 416s

[@thetest8777]

And pof 416 😂

[@FishFind3000]

Forgot to mention its better when running a suppressor since you don’t get all the extra back pressure dumping into the receiver.

[@dekuthedog]

Better is subjective here. It depends on the goal of your suppression. If you tune your gas system on an AR properly to run suppressed, it will be more quiet than any piston system.

[@frankbrowning328]

On an adjustable gas system piston gun it also prevents some the the gas from coming back at your face

[@Pyreleaf]

Technically, yes, because suppressors do force more gas into the upper receiver; however, if you have an adjustable gas block on a DI gun, then you should also be just fine.

[@kxkxkxkx]

Dumb and totally wrong 🎉 congrats

[@CallsignWulf]

Can always get flow-through cans. I doubt they eliminate all of it, but seems a lot better to me since it doesn't drastically change the gas in the gun.

[@hcaseyk]

I learned a lot from this video. Well done Steve and Caleb. 1 question I have is how can I get a cut out of the AR shown in this video?

[@mghegotagun]

This timing is unreal. I was just re-visiting my PWS vs DI build decisions this morning.

[@nunyabinness3574]

I love firearms cutaways...3D works of art!

[@John-ro3vu]

Good video! Now - BRING BACK THE BRN 4 LOWER 🙌

[@vanvino4074]

For me the biggest benefit for a piston is less gas in my face when shooting suppressed as a leftie.

[@DevonReclaimed]

Considering that my sig Sauer 516 was designed by the same man who created the HK-416 with various improvements I think I'm in good hands with it besides the proprietary handguard situation which seems to have been solved on the subsequent Caracal and Haneal rifles. Shame those are hard to get in the USA

[@mondrianbogert6835]

Might be a moot point now with Haneal getting slapped by HK for patent infringement.

[@96SN95]

The Sig 516 is an underrated rifle.

[@michaelsmith3381]

I have had my 516 Gen 1 for almost 9 years and never a ftf fte or any other issue. Runs great with a can and without. No matter the temp, over 100 or well below 0 it just shoots.

[@EgoBro]

03:36 Lol, I am now in Ukraine and the first thing I did after buying my ar-15 was to install a gas piston. A somewhat emotional decision since after that I saw many video reviews confirming the overall reliability and unpretentiousness of the original DI system, but I do not regret it. In any case, I can always go back to DI.

[@sixpest]

You own a piston now you aren't missing out on anything The di only blows garbage away from the carrier and runs cooler where you hold it and is a little lighter Id say you're doin good

[@EgoBro]

@@sixpest Thank you, you are right. I can but wouldn't want to go back to DI especially considering how much better I am with a piston when using a suppressor. However, I would like to warn those who, not knowing the exact advantages and disadvantages, immediately install the piston on their ar15. It's not always easy to install out of the box (as is the case with my iwi zion), incurs additional costs that you could spend on buying attachments for your ar15.

[@loboloco866]

Great review

[@reginaldlittlefield5580]

I have a Bushmaster AR-15 that I converted with an Adams Arms conversion kit from Midway about $200.00. Runs great and no blow back when suppressed. It also has a suppressor setting.

[@michaelfregoe5875]

I definitely noticed the extra weight of the gas piston AR that I shot. Each to their own.

[@michaelolexa4147]

well, you might try the CZ Bren 2, it is lighter than most AR's, and is a short stroke gas system. like all the rifle they DIDN't talk about

[@socmonki]

@@michaelolexa4147 They didn't talk about them because they're comparing DI vs Piston ARs. A Bren isn't an AR.

[@clutchboi4038]

@@michaelolexa4147 lol lighter because it has a plastic lower and basically non existent hand guard with no mounting options or a stock. If you stripped down a 416 to have a plastic lower, no handguard and no stock it would probably weigh the same if not less.

[@muddyhotdog4103]

@@michaelolexa4147 it's about where the weight is, which makes it front heavy.

[@Jrhoney]

The long stroke gas piston setup in PWS rifles is king.

[@lance862]

I'm glad you brought up long stroke piston guns... PWS makes an AR long stroke piston variant that is very nice.

[@KendrasEdge757]

My LWRC piston guns run flawlessly. If it’s a built piston gun it typically runs flawlessly. The Adam’s arms conversion kits can have problems. I didn’t have any with one I built but I only had 1500 rounds through her. DI guns are typically cheaper and lighter, but can’t say ones better than the other. Depends on what you want.

[@KendrasEdge757]

@@556bc whys that funny? To make more money? There’s absolutely nothing wrong with their piston guns, or their DI guns that I’ve seen. I’ve got multiple piston LWRC guns. They make some of the best ss piston guns out there. They’re not making DI’s due to any issues with the piston versions that’s for sure.

[@JohnBrowningsGhost]

@@556bc funny how? The market wanted a DI gun from them and it’s the cheapest rifle they make and probably a sales leader.

[@9770G]

Ya I’ll take a quality DI ar15 over a Piston one any day of the week. Piston guns have more moving parts for the weapon to function. If one part fails the whole system does. DI > 100%.

[@KendrasEdge757]

@@9770G lol that’s an ignorant argument against piston guns usually made by those that have never owned them or only owned some bs conversion gun. They’re well proven, extremely robust and reliable platforms. To say otherwise is just ignorance of them. There’s nothing particularly unreliable in a factory piston gun just like there isn’t in the vast majority of DI guns; even the $400 BCA guns will run just fine and just like a DD or bushmaster or colt DI. They just cost more because your payin for their name. Everything requires proper pms and all have wear/maintenance parts that need replacing and anything man made can fail. Whether it has 3 parts or 13 parts, it doesn’t matter.

[@9770G]

@@KendrasEdge757 it absolutely matters. The more parts u have needed for a system, the more parts u have to worry about failing. DI’s have very few moving parts to function. For that reason alone I would chose a DI over a Piston Ar. Secondly DI Ar’s have been proven to be extremely reliable. Lastly, there are far far far more DI Ar’s out there than Piston ones so in a SHTF situation u would be a fool to think u will find a replacement BCG a for your Piston ar before a DI BCG. Oh and I never said Piston Ar’s weren’t reliable. U need to learn to read better. All I said is they have more moving parts which is a bad thing.

[@drcoffee5588]

I bought and immed sold a preban ar15 20yrs ago because it was a dirty pig after just one mag. I hated cleaning it. For those who Love the DI AR the gasses that blow into your face are carcinogenic. Breath deep 😂. I finally found an affordable piston AR. The Wolf A1 upper Tiawan T91. Military designed. No gas settings, runs cool, clean and reliable. Not the perfect AR, but perfect for me. BTW conversions rarely work out.

[@scottlehman9738]

Great video and thank you.

[@JamesS.254]

My Adams Arms piston upper has worked great so far for me, I’ve had it for roughly 10-12 year’s. Admittedly it only has approximately 400 rounds through it. My reason for switching to piston ( and I’m surprised it wasn’t mentioned in the video) at the time was due to the gas in my face when suppressed, even with glasses that sucked. Gas buster handles didn’t help at all for me. I will say though, on my 300 BLK pistol, and my 22” 6.5 Creemoor rifle, adjustable gas blocks have worked very well when shooting suppressed.

[@alcopower5710]

Same positive experience with my Adams Arms AA15

[@cameronmolt5649]

My Sr556E has been a great rifle. It's front heavy.

[@HugeCockAndBalls]

still just worse than a normal AR lol

[@barfo281]

I won't say I have Ruger SR556 (original, which was about $1600) and Ruger MPR ($700ish).....but both function just fine and are soft shooting. MPR is lighter, though.

[@deltatwoniner96]

They both have their pros and cons for sure. Try to shoot them both and decide for yourself which works better for you. The average American qatching this isn't on seal team 6 or in a squadron 1st sfod-d. Direct impingement is cheaper and dirtier but also maybe a little more accurate. It's really personal preference. Been shooting ar15s since 1985, then m16a1, m16a2s, m4s etc. I personally never had a problem with any of them that wasn't ammo related.

[@frankbrowning328]

Excellent point about ammo choice. I'd also add poor maintenance to the list of reasons why most systems fail prematurely

[@twelvepercentitalian2511]

My problems always came from the magazine (until Magpul cam out) and not enough lubricant on the BCG. Mobil 1 or M-Pro 7 takes care of that issue now.

[@mosulmedic7048]

Not many people reference one of the largest factors that lead to seeking piston driven rifles. Maritime operations. Water was one of the main factors that led to pushing for piston rifles for standing militaries. Water can cause catastrophic malfunctions in DI systems. The same (generally speaking) isn't true for piston. For those trying to decide if they want a DI or piston driven AR, ask yourself these questions 1. Will you be shooting full auto? 2. Will you be using it in water? If no, then buy a DI.

[@MikoTactical]

Love my LWRC DI, would like to get my hands on one of their piston guns.

[@frankbrowning328]

Yes, piston guns (when the piston is properly done) are better for a few reasons. Good piston guns have an adjustable gas setting which helps tailor the rifle for the power level chosen. The piston set up stops most of the gas from going into the action spraying fouling throughout the action. A good piston system greatly reduces the heat in the reciever. Reduced heat and reduced fouling allows the parts to experience less wear and tear. As said in the video the Sig system is a very good and reliable system

[@03redrubi]

Too muzzle heavy for me. It's just a matter of preference really.

[@phattyre1830]

Piston system put a lot more stress into the bolt lugs than Di does. Not just from carrier tilt but also it acts like a slide hammer on the lugs by driving the bolt carrier and bolt back at the same time. Where as on Di the bolt actually goes forward a bit when opening from the gases trying to force the carrier and bolt apart, taking stress off the bolt and extension locking lugs. Even on the HK 416. While the barrel may last longer the bolts typically break a lot faster. They also loose headspace much faster.

[@03redrubi]

@@phattyre1830 Although the heat is concentrated around the piston block on the barrel. A CHF/CL barrel, on a DI system, would probably out perform in longevity.

[@frankbrowning328]

@@03redrubi To each their own. It really only adds a few ounces when you compare them with the same barrel profile and handguard

[@phattyre1830]

@@03redrubi if you could get less wear and stress on the bolt and extension lugs. A piston system would last longer. Heat is a major contributor to what kills a barrel. Usually you burn out the throat first. Piston gun would definitely win there. But when it comes to bolt breakage Di wins, piston system usually have massive lugs because of this stress. The ar 15 many lugs are just to small to handle that stress.

[@Ratkill9000]

Another thing where DI shines over piston, more options with longer barrels. I think the longest piston upper I've seen might be 18". Also piston I believe tend to run short barrels more reliably than DI.

[@PBVader]

20" POF 308. Early version with carbine buffer and mid length piston. Talk about an overgassed mismatch. Heavy buffer tuned with a bcg centering cone. Runs like a sewing machine and I love the benefits of a carbine buffer tube.

[@CxS_Nico]

I have a 20" LWRC REPR (Piston). LWRC still produces 20" barrels till this day.

[@Ratkill9000]

@@CxS_Nico I was saying it's hard to find piston uppers with longer than 16-18 inch barrels.

[@CxS_Nico]

@@charlesmciver897 I wish brotha, mine is the MK1 REPR. The early MK1s had magazine fitment issues. Mine is a later model where they fixed those issues they were having with the earlier guns. She runs flawlessly.

[@bartb7790]

Standard 20" HK417/MR308/MR762... The piston and rod are the same as for a 14.5" HK416.

[@user-rb9kr2tn9m]

A year ago i bought the LMT Estonia R20 rifle that is piston driven a i LOVE it it runs SO clean!! A little stubborn on reloads if they aren't pushing max loads. But all in all a greaat rifle

[@ge0arc244]

Didn't know about the bolt tilt on cheaper AR style piston conversions. Made a lot of sense why they fail earlier than gaa style systems they are meant to be better than. I currently run an Adam's Arms piston system AR on one of my rifles and checked to see if the bolt carrier was lined up properly to avoid bolt tilt. It seems to be. Never had any trouble with it, But will keep an eye on it for tilt wear. Thanks for the info, Good Stuff Sir!

[@Wk-is8eh]

I found Iraqveteran8888's meltdown videos to be really informative about various piston AR's

[@9770G]

The Piston ar’s failed at the same point the DI guns did but for different reasons.

[@zoltancsikos5604]

​@@9770GIt's hilarious watching you function on nothing but copium. What a triggered DI fanboy.

[@floridahdshooter]

I find interesting they did not mention the BRN 180.. Over time I have converted to all piston guns. in my experience they are just more reliable. I have had DI gun fail in training, in competitions and such. I have never had a good piston gun fail. I have a BRN 180 as my comp gun and after rebuilding my Mk18 for the 3rd time as it tends to destroy itself I went MCX and have not had a single problem.

[@huffthomas1]

The 180 uses a different bolt/carrier and recoil system than the AR-15. Hence, not technically an AR-15. I imagine that's why it wasn't included.

[@karlkiessling3785]

Great video! Steve and Caleb, as my collection is growing I'm finding it difficult to keep all the spare parts organized for my various firearms. What do you do or suggest to stay organized?

[@SoloRenegade]

the gas escaping from the bolt also serves to clear the ejector port of debris with DI. positive side effect.

[@KB-kw8ni]

Direct Impingement is now known as Direct In-Piston

[@doncarr9860]

It's just the bleed off of political correctness.

[@mjcmustang]

The other advantage of DI is if you have debris, dirt, mud, or snow on the side of the BCG (dust cover open), the exhausted gases from the system are expelled through the side of the BCG which has enough force to push away debris, mud, snow, etc.

[@9770G]

Yup which is a big reason why DI is better than Piston.

[@zoltancsikos5604]

​@@9770GKeep telling yourself that.

[@tacticalbt1023]

Both great both work.

[@C_oprator89]

Pws has entered the long stroke chat

[@hairydogstail]

Internal piston (so called DI) is better than an external piston in the AR platform. If you like more recoil, less accuracy, more cost, less life of the rifle then by all means get an external piston rifle.Heat has no effect in the bcg as long as it is kept lubed and is more reliable in every mud test.The vent holes blow ingress out the ejection port the external pistons won't.. The piston's only advantage is with suppressed shorter barrels as the external piston is more self regulating..

[@Jammaster1972]

perfectly stated

[@zoltancsikos5604]

Pure nonsense from start to finish.

[@hairydogstail]

Explain why or are you just trolling?@@zoltancsikos5604

[@gunsnslings]

Strictly speaking, the original AR system is also a piston system. It's just that the bolt carrier serves as an inline piston. The fact that the piston is inline with the bore, combined with the fact that there's no reciprocating mass attached to the barrel, means that the AR operating system has better potential accuracy than any traditional piston system, HK included. It's a brilliant design, really.

[@Andrewsky347]

Not only that, it also resists shearing the locking lugs by actually pressurizing the bolt forward as it's camming it.

[@zoltancsikos5604]

Pure nonsense.

[@tactical-dad]

Very interesting. Thanks an greetings from Germany

[@aiartificialintelligence5024]

Thanks a lot for good explanation 😊

[@Paladin1873]

The only advantage I see in a piston driven gun is if it's being used as a squad automatic rifle. I have a few piston rifles (SU-16, AR-180, Adcor BEAR Elite). The BEAR is the only one I would seriously consider using as a combat rifle. It does not suffer from bolt carrier tilt or mediocre accuracy (thanks to its free floated barrel), but it does mean having to tote around more weight. I think I'll stick with lighter gas impingement ARs.

[@davidmeeker7481]

I own a Daewoo DR which is a hybrid of AK gas piston with AR bolt. I think it's the best. I also own a Taiwan T 91. It's great too. The recoil impulses are way different in each but both run smooooth.!! And of course I own several DI ARs. They all seem to run fine.

[@TiTan0s]

How often are you guys going to restock the BRN-4? It's amazing but I dont think I've ever seen it in stock (at least with my timings 😅)

[@drmurda]

FELLAS, You hit a great topic. Please do more like this.

[@PBVader]

I have an early 20" POF 308. Overgassed and reality of BCG tilt chewing on the upper, not necessarily the carbine tube. Love it tho, now with tuned and BCG centering buffer.

[@highseassailor]

Built 2.5 ARs from scratch, all with Adams piston systems. The .5 was a PSA upper, and now its not! Once the POF roller cam pins were installed, and the gas ports on the barrels where enlarged, I found flawless operation. Having been prior military and had to clean 100% of the carbon from the bolt and carrier groups, I was excited to never have to again!

[@ashlandgunclub1000]

Caleb’s hair is made by Mattel just like the original M16 plastic 😂😂😂

[@kodiakkeith]

A dozen or so years ago I bought a cheap Windham AR and a number of spam cans of cheap Tula 5.56. This was when the question of aftermarket piston kits was a hot topic, and I found the dirty Tula would begin to see failure to feed or other malfs after about 200 rounds. I put an Adams piston kit on there and it would just run and run and run with that same awful ammo. I still have that rifle, it's never had another malf and it's my go-to AR. I probably have 3-4k rounds through that rifle now, without a single hiccup. And yes, I know if I ran cleaner ammo in my original "test" it likely would have run just as well with the original DI system. I suspect most people that have run into problems with aftermarket piston kits simply don't oil them once in a while. Just put a drop or two of CLP in the piston end (depress the piston with a bullet tip) and do the same at the other end. That's about the only maintenance a piston AR really requires. Your bolt and receiver stay clean and cool and rarely need cleaning, just a bit of lube now and again. Why do this if clean ammo will run well in a DI? Because with the constant political battles over guns, you may damned well find yourself limited to those cheap spam cans you keep for SHTF. A piston AR will run anything flawlessly, while a DI not so much...

[@Ephem13]

I always come to the "It depends" stance as well. I tend to go with DI because I don't have a need for anything else, or a piston just isn't an option for the build.

[@skogox84]

I have had no issues with my Adams Arms kit. Granted I have only put 2k rounds through it. I think why it runs well is the special BCG which is lightened in the rear end of it.

[@paulhafner9781]

Cleaner and cooler sounds like a win for most heavy use applications.

[@DragonJohn]

I got an Adams Arms system when I built one a while back. but it was a kit with gas block, carrier and upper receiver. I had some problems in the first 50-100 rounds with short stroking but after that I haven't had any issues. What I really want you folks to do is get the BRN-180S in 7.62 in stock

[@saltyroe3179]

My dad the engineering professor said that engineers learn when people die. I for sure would not want have had gotten the 1st issued M16 in Vietnam without cleaning kit and with wrong amo.