Tips on building a reliable 9mm AR-15

[@craigfuhr]

Quite possibly the most informative video I have seen yet regarding how to properly build a functioning 9mm AR. I can't thank you enough for taking the time to fully describe all the parts you used. I am currently building my first AR9, and needed this exact video! Thanks so much, young man. Keep the GREAT videos coming!

[@joshv06]

Thank you man, I got a new video coming where I'm modifying a CMMG RDB to fit into an EP9

[@devinsmith2717]

I agree, currently working the kinks out on mine. Went with a blitzkrieg hydro. Buffer and a regular old .223 spring and i have a feeling now that it may be the wrong setup after watch this. Great video!

[@franksimon8375]

I'd rather govt subsidize actual good educators like this gentleman than the trash we have "teaching" in schools.

[@mousetoad7040]

Adding quarters to a standard AR carbine buffer spring stiffens it up to make it stiffer like a dedicated 9mm buffer spring (I've been told). Dedicated 9mm buffers are heavier than standard .223/.556. It seems counter productive to weaken the spring and than add quarters (?)

[@TheCivilWarriorProj]

The quarters ensure the BCG doesn't slam into the rear of the receiver. They provide stand-off if you will.

[@kittrainbow7]

It's an excellent video, my ar9 it is like yours, only I have the sidecharger model. I experienced the same problems: 1 the fake "gas key" separeted, easy fix: clean the screws and apply loctite treadlocker. 2 at about 3000 rounds, the original firing pin, snapped in two parts and the head had a mushroom deformation, clear sign of bad heat treatment and probably also bad material. Now I have a better quality firing pin, always with its spring for safety. 3 the bolt had a sharp corner that caused unusual wear on one feed lip of the ETS mags. It needed a little bit of filing. But in general the bolt with the 223 extractor is excellent, way better than the old ar9 projects. 4 some sharp corners around the charging handle needed sanding. 5 the sidecharger handle required tuning, sometimes it didn't stay closed at the last round, the retention detent it's not a great solution, especcially with wear. But the sidecharger is really handy in competitions, also the working bolt release on last round. I really like mine, it is extremely reliable and with the awesome ergonomics of the AR platform, even with the minimal tuning I think that it is way superior to many other SMGs/9mm carbines, that also have their problems. Again great video👍

[@jamescdean9010]

Holy Cow! I'm just starting an AR9 build and the variables are a lot to take in. A Bear Creek 7.5" 9mm upper on a PSA lower. Lots of issues so far, but dang, I'm gonna make it work.

[@ofacesig]

I've now run black Creek and qc10 Colt lowers with ballastsic advantage and CMMG barrels respectively. Feeds all FMJs and Federal HSTs with zero issues.

[@thebardock6785]

Did you run anything before that? I was thinking of getting a block for s&w mags

[@sallutz]

This is one of my fav goto videos when I did my first ar9 build. Great info. Been subscribed to your channel for a while now....looking forward to some new videos on the ar9 or other ar pistol builds or parts reviews. Thx

[@joshv06]

Thanks man. I plan on doing more once the cold weather goes away!

[@300whiteout9]

This is my second time here lol

[@alecubudulecu]

Such an awesome video man. Love how you explain stuff. I built my AR9 already and functions but the explanations you give helped shed light on a lot of things I was confused about. Also saw your other vids. Your tech background explains your detail oriented nature. Good stuff man!

[@joshv06]

Thanks man, I really appreciate it! I've been needing to find time to make more videos, but been busy running the business!

[@hermanmunster4387]

Great video my AR 9 works flawlessly now after watching your video. 👍

[@joshv06]

Great to hear, brother!

[@Kettenhund75]

9:17 Your feed issue is due to the stiction between the steel cases and your magazine, not because of the type of bullet you are using. Steel is just not as slick as brass, and plastic grips it more. You can see the round pivoting on the front of the feed lips of the magazine - the round is pointed at the barrel extension before it ever gets to the feed ramp.

[@izyb6608]

Don't hear "stiction" much outside of motorcycle tech... :-D

[@FUBARguy107]

Aero has acknowledged that it doesn't matter what ammo brand you use, hollowpoints suck at feeding in AR platforms. The "feed ramp" isn't really a feed ramp at all.

[@tylerlegg3069]

I'd have to disagree. I've never put steel through mine and it jams all the damn time. Hollow point or not, doesn't matter. After a little bit of carbon build up gets o0n the back of the barrel it's game over as far as feeding goes. Never buy angstadt arms. This was happening with there UDP-9. Zero customer support. wasted $1,400 on a POS that jams after 200 rounds.

[@theMelvster6]

I ran NFA receiver set. Super sloppy fit but it worked. I ran Foxtrot Mike Products FM9 bolt which I milled to clear the barrel feed ramp, the taccom 3g pcc buffer system and their 5.25” ramped barrel. I had to modify the length of the buffer and run a flat wire spring to work with the LRBHO more reliably...however it fed anything reliably. Ball ammo, flat nose, my defense round was federal 147gr hst. Never had an issue with feeding, extraction, or LRBHO. I sold that 9mm pcc a few years ago because I hated the fitment of the NFA receivers.

[@l337l0gan]

I'm testing my ar9 today for the first time. Gonna try the Endo mag conversion kit first. I think I will throw a couple quarters in my buffer tube as well. I wish I would've wore my standard spring out before now

[@j1ivibo]

Howd the testing go? I tested mine with endomags a few days ago and today. Was having ftf but started working. Still jams up here and there. Waiting for my heavy buffer to test it out. Hopefully itll feed well

[@l337l0gan]

@@j1ivibo I had issues ejecting. It fed, fired, and extracted fine but 50% of the time the ejection would just fumble around in the chamber. I purchased a magwell conversion block and haven't had as many issues now. I may have 1 failure every 100 rounds now. But the Endo mags I was having 1 issue every 2-3 rounds

[@j1ivibo]

@@l337l0gan damn. Mines the opposite. It fired and ejected fine. Just chambering was the issue. Which mag block did you go with?

[@l337l0gan]

@@j1ivibo I bought a promag. It's a cheaper one. Cost me like $45 or something. Colt smg style mags. It's been good and LRBHO has been working fine. My metal mags work great but some of the poly mags I had to take a Dremel and some sandpaper to the lips just a tad before it would seat on a closed bolt

[@ericchristianson8190]

Very useful vid, particularly the comment about weaker buffer spring.

[@joshv06]

Thanks man. It helped a lot with preventing nose dives on bullets

[@doddgarger6806]

Yeah bolt velocity is critical for proper function with these blowback function systems My BCA ar9 upper feeds perfect by hand with endomags but only runs 115s with a 12oz bolt and 8oz buffer, gonna try a 11oz buffer and see what spring works best , won't run 124s stovepipes every other round seems like

[@CaptainFADC]

"... But JHP doesn't feed properly... But watch, it will work perfectly on video...". Murphy's law hard at work. Good video, my dude.

[@joshv06]

For sure. Murphy's law will get you when you need it most. Which is why I use my roni as my defensive subgun with gold dots.

[@theMelvster6]

Use a ramped barrel like the taccom 3g ramped barrel and it’ll feed JHP without issue

[@mikewho822]

At 7:49, was that a ricochet?? Heard a zinger, sounded like it flew by the camera. 😳

[@roddymcclain]

I had the same problem with the nose going downward. Taccom3g has a stainless steel deflector that redirects those nose down feed problems up into the chamber, both round nose and hollow points. you have to file some upper receiver next to the barrel face. I used an ignition point file from oreilly's. Just follow the instructions they send with the defector. They say to friction fit or glue it in place, I chose to keep it barely loose so I can thoroughly clean the upper. If I were to take the upper and lower apart it would fall out.

[@joshv06]

I have since put the Taccom feed ramp on and it works fine now.

[@pdog305301]

great tips on ar9 reliability. just ran 3 quarters w/carbine buffer and nfa buffer spacer worked very well. only 2 ftf w/ets mag stock glock 33 rounder was 100% reliable

[@joshv06]

ETS mags have a lot of drag in their mags. Glock mags have a steel inner lining and feed up quicker which give less feed issues.

[@frankv3424]

Just finished build had a few problems, had a few hang ups and buffer spring pin snapped twice on me any ideas why ?

[@jimfaley1831]

The Winchester Silvertip is a hollow point that is narrow at the tip

[@jeffreyMagnum460]

What would cause the firing pin to have soft strike on primer, firing pin moves freely and it will protrude when I remove spring from firing pin.

[@ArcticProxy]

I generally would prefer building the gun, but my EP9 is the best value AR-9 I could get for the price. It's a fantastic pistol.

[@brysonw1815]

Nice ar9 my setup is Angstadt jack 9 reciever set QC10 3.5” barrel SLR 4.75” rail TAccom extreme BCG Spikes 7.7Oz buffer weight Spikes buffer spring SBPDW brace BCM enhanced LPK Magpul pro flip ups Sig Romeo 5

[@austinporter9232]

Built an ar9 and the rounds either get fed right into the bottom of the barrel crashing into the mag well basically, or it feeds but the round gets dented and pushed in sideways

[@joshv06]

What buffer, spring, barrel, mags are you using?

[@austinporter9232]

@@joshv06 Standard glock 33 mags, 308 buffer spring and i think a heavier buffer tube as well

[@joshv06]

@@austinporter9232 I would skip the 308 buffer spring and go with a carbine spring. Then 308 buffer spring is giving you a fast forward feed rate

[@4g63mark]

Lapping the upper receiver and touching up the feed ramps with a Dremel will fix your problem with the hollow points.

[@joshv06]

Not really since glocks feed down the middle.

[@MetalShredder22]

Awesome video man. Great info. I'm just starting my ar9 build. Blade and tube kit, PSA PA-X9, and ambi SS is what I've got so far.

[@ParaGIexpert1911]

Last time I watched one of your videos I built a 7.62x39AR. I am now thinking that I may need a 9mm AR. Thanks. By the way that skidtactical 7.62x39 ar bcg is outstanding.

[@rloco6628]

KyFirearmsChannel What spring would you recommend for a AR-45?

[@KiaSorento-tu5op]

Good job. Very informative! I love learning about ar9s

[@joejeans7913]

mine dont even think about feeing lat tops with my Faxon barrel spikes upper and lower. had to get a taccom feedramp.

[@joshv06]

Has that for a while. But there was still a small gap where the flat top could stop on the feed ramp.

[@joejeans7913]

@@joshv06 gotcha I heard that macon armory actually has a fix, I just emailed them , curios to see what the fix is. thanks for the reply . love the sound of your setup, I load super heavy low power 147 also I bought some 160 gr bayou bullet Co, have tried a few loads already out of my glock only doing 590 FPS, not much Data on the load that I can find just doing a ladder load now. working my way up. I just ordered a Omega36M and a Octane 9 to run hopefully will get sometime by summer .

[@abolishtheatfandrepealthen6014]

Good vid. Doing a dedicated 9 now. Probably going to try the macon armory buffer and barrel

[@indianalex01chief]

Great video. I am going to get a KAK buffer. I have a full auto colt. Getting bolt Bounce. I have a solid buffer.

[@lazerrred]

Very good information. Thank you. Subscribed. 👍

[@SALTYCOMBATDIVER-ExInstructor]

Some Glock compatible bolts don't work with Colt style mags/lowers. And compressing a spring doesn't weaken it contrary to what so many claim.

[@DennisD441]

I’m building another and this is great info exactly what I’m looking for!! Thanks brother!!! AND, I’m going with the Faxon barrel as I’ve heard all good thIngs and Davidsons has them on sale and it’s 10-15-22 for anyone shopping!!!

[@crdwzy4688]

Wouldn't a steeper feedcone help with them hollow points?

[@joshv06]

Sorry, in the video, I meant steep in the other direction. But yes, a deeper/lower feed cone is always better. I send mine to Macon armory to be redone

[@glc5858]

Ar 15 9mm need a 8 to 9 Oz buffer and a reduced power carbine buffer Spring. The buffer spring is only pushing a 9mm into battery.

[@007blurivr]

Taccom aftermarket ar9/ar45 feed ramps for $20 fix the hollowpoint (or any) feeding issue. They work great in my ar9/ar45! chk it out

[@JenkinsStevenD]

Unfortunately those seem to interfere with the dedicated 9mm lowers that have a built in LRBHO. Additionally, I don't believe they help if the cartridge is feeding too high which I guess is incredibly uncommon. Good recommendation for those without the LRBHO though!

[@thebardock6785]

You can't use hollow points on yours in particular any idea on how to avoid it?

[@joshv06]

This fixed my hollow point feed issues 100% taccom3g.com/product/taccom-glock-lower-feedramp/

[@thebardock6785]

@@joshv06 thanks

[@antone35]

Great video a lot of good info thanks I got one question hopefully not to dum it’s about the quarters in the buffer what do they do and dose every build need some ?

[@aarondmason808]

The quarters in the tube limit bolt travel to keep bolt velocity down so you don’t snap off your bolt catch. I’d recommend adding the quarters even with the correct length bolt. I add quarters until there’s almost no bolt over travel.

[@antone35]

@@aarondmason808 thanks for the info I will add a couple quarters 👍

[@legionnaire5966]

Spinta makes a great Glock 9mm bolt carrier group!

[@TheCivilWarriorProj]

So my buddy approached me to build a single shot AR9 suppressed. Any recommendations on how to accomplish that?

[@joshv06]

I cover that in the video.

[@skippythefreak91]

taccom extreme feed 9mm barrel. it will change your life.

[@kingsofglamis9576]

skippythefreak91 were did you find that barrel

[@Killa91115]

You should put links for the parts

[@joshv06]

I'll get a KZbin strike for that unfortunately.

[@Killa91115]

@@joshv06 smh well that sucks. Hopefully someone will come up with a platform called freedomtube lol

[@thebardock6785]

Nice tip with the quarters

[@daveperala4723]

Finally someone else that not only knows about putting in a quarter or two but actually admits it. Tell some guys about it and get nothing but a blank stare back.

[@lazerrred]

LOL....... I know what you mean, like - duh.? Some don’t know that certain timing can make it happen or not on any mechanical device.

[@WVdavidB]

I didn't know till I saw it here! Lol. I kept thinking people were meaning something about quarter circle ten. I'm about to build me a YHM new billet block lower/9mm upper AR.

[@mousetoad7040]

Putting quarters in is to stiffen up a standard carbine spring as 9mm springs are stiffer than standard AR carbine springs I am told. Weakening the spring and then adding quarters is contradictory from what I understand. Am I wrong?

[@MrGunnerru]

Mine breaks firing pins a lot.... dunno what to do with that.

[@bds6920]

My barrel into my receiver does not use a barrel nut--just clips in---and there are also 3 washers-where they go I do not know---it looks like the whole thing is held by the m lock hand guard-can you elaborate

[@joshv06]

What company is it from?

[@ironsights7028]

Nice build. I have the same buffer set up, and lower. Change out the stock mag release for the odin works model. Its works perfectly. Much better than the stock one.

[@joshv06]

Thanks. My build works perfect. I love it. I need to reload more subsonics for it.

[@neudimensions1320]

The bolt hold open is actually part of the upper.

[@joshv06]

Correct. And the link bar has to be positioned with the lower's magazine using their NFA lower.

[@neudimensions1320]

Thanks for the video. Building an ar9 myself so trying to gain as much knowledge as I can.

[@mousetoad7040]

@@joshv06 Some uppers have it, some don't. Some are restamed .223 uppers with different bcg and barrel Some lowers have it, some don't. AAO carries 80% lowers with and without.

[@bigguy6439]

What barrel you got. I seen one with a ramp. Barrel but it cost $170. Or a $79 is good buy

[@joshv06]

Faxon is the way to go

[@beanz0248]

What is the proper nomenclature for silver curved piece just forward of the trigger? You're touching it with your thumb when you begin speaking about the lower. Is that for the LRBHO, mag catch, or extractor? Mine came out on my AR9 and wondering if its a simple fix with 4-40 screws or is that something I need to send back into the manufacture.

[@Spiriteagle114]

I'm using Stern defense BU9 9mm glock cut BCG (15.5 oz with weight on, 13.5 without), and arguing between an 7.7oz spike tactical buffer or a 11oz Stern defense buffer (also using stern's mag9 magwel adapter). Since this is a glock set up, should i run the 11 oz first and see how it goes?

[@walterjas1]

Nice job you will only get better .

[@jestonjump5647]

For my buffer set up I have a flat wire spring and a hydro buffer. Def reduces over the standard 9mm set up imo. Only problem with it is it’s a pain in the ass to get in and out of the gun.

[@jestonjump5647]

Reduces recoil***

[@joshv06]

Do you have a 5.56 flat wire spring or .308?

[@jestonjump5647]

i want to say i use the .308 but i'm not 100% got it over a year ago. i got it from davidtubb.com he has a good video explaining the advantages of the flat wire spring. i'm sure if you email him he will gladly tell you what spring to use.

[@joshv06]

I used to use the same spring and the forward bolt velocity to way too fast. Bullets were getting dinged up and set back into their casings. It's better to have a heavy buffer and weaker spring.

[@jestonjump5647]

maybe i'm not having that problem because i use the 9mm hydraulic buffer. I had to cut a few coils off the flat spring to get my last round bolt hold open to work... any way great video keep em coming.

[@strykeback1]

What buffer tube are you running with that shockwave? Looks a bit longer then my basic one that xame with a kit.

[@joshv06]

KaK dimpled tube

[@MrTangoRomeoDelta]

My KAK buffer doesn’t rattle like yours, did you remove the rubber spacers to have more of a dead blow effect?

[@shanebeaudrot777]

Good info, thanks for sharing

[@Randanator65]

Im having an issue where my glock/pmag 15 rounders are feeding beautifuly but i throw in my glock 31 round mags and wont feed at all just slams the bullet into itself smashing it into the casing and its only for those extended glock mags any suggestions where i should start???? Im new to this so any advice will help, thanks guys great video too man.

[@joshv06]

Thanks What Barrel is it?

[@Randanator65]

@@joshv06 i bought the upper with parts kit from psa its a 16"inch gen 4 barrel appreciate the response man,

[@joshv06]

@@Randanator65 might want to contact Macon armory to contour your barrel extension. In the mean time, I would suggest to leave your bolt locked back to weaken the spring and to get heavier on your buffer. I suggest the kak 9mm buffer. The heavier the biffer, the higher the bullet hits on the feed cone.

[@Randanator65]

@@joshv06 ok thanks man so much man ill let you know how it goes thank you man have a goodnight brother

[@Vleegz]

Thanks for the video. Have you heard much about needing to headspace check a new 9mm upper? thanks!

[@joshv06]

Headspace definitely not needed 👍

[@Vleegz]

@@joshv06 thanks. Just not wanting my gun to blow up you know? Is it true it's different for blowback guns?

[@250-25x]

Thanks for the info! I have the Davidson Defense 9mm Conversion system on the way, and I will be trying it out on a Polymer 80%'er I just machined. Total test bed deal, but should be fun to learn the 9mm AR game. Have fun, G.

[@joshv06]

Nice! Best of luck!

[@mikejohnson9118]

Josh, How does the lighter spring/heavier buffer work unsupressed? Or do you have a different setup for Supressed--Unsupressed? Thx MJ

[@joshv06]

Run all with the KAK 10oz buffer and same spring. Works fine with or without a can.

[@bammiracle4192]

What happens with a heavy spring and heavy buffer? Im having issues getting into battery and my extractor isn't grabbing the rim of bullet..

[@joshv06]

Seems like you have another problem honestly.

[@johnlumpkin3082]

Anybody else have a problem with mags being hard to insert? My mag well is awfully tight. I'm using aftermarket mags, but have a couple factory Glock mags ordered. Ideas?

[@plugBONE]

Why a feed cone instead of ramp?

[@joshv06]

The blow back bolt does not use a traditional barrel extension

[@plugBONE]

joshv06 thanks!

[@petefernandes1413]

I'm having problems with my trigger depressing enough to grap the "restart sear or ledge" Not sure what its called but the hammer is just following the bolt home resulting in a dead trigger. I also just broke a firing pin today but it had a few 1000s rounds so I hope it was just wear. The trigger thing I can't figure out.

[@joshv06]

Is it a milspec fire control group?

[@petefernandes1413]

Nope. I did some research after this comment. I put a sd3g trigger in the build. I have a cmmg ramped bolt and come to find out there is only a handful of triggers that it will reset. It runs milspec really well. I honestly don't want a milspec trigger so I'm going to call cmmg tomorrow and see if they know any non milspec lighter triggers their bolt will run. What trigger did you go with? If so what is your pull weight?

[@ca5ualm3dia]

so do i get a better barrel or install a feed ramp to run the better jhps ?

[@joshv06]

Both

[@scottm5001]

Why won't hollow points work? I k ow for a 1911 the problem is solved with anti tilt mag followers.

[@youngboyharless9769]

The angle of the bullet gets caught up trying to feed, Flat-head style hollowpoints will give you problems. Stick with ones that are more narrow /^\

[@sorenfisher344]

Hey man great information, I just finished building my ar9 Glock set up. Shot it for the first time today, had the gun cycle well. It extracted perfectly and picked up a round everytime. The problem I had was my trigger was not resetting it would only reset if I manually pulled the charging handle. Thoughts?

[@juanc.1279]

Bolt isn't traveling back far enough. Had the same thing on a blackout

[@sorenfisher344]

@@juanc.1279 Actually no, i figured it out. I failed to install the trigger disconnect spring. Thanks for the input though.

[@DennisD441]

Yes on the hollow points unfortunately. I found out the hard way how compressed/smashed they get!! Destroys the expensive ammo of course!!!

[@jacobgonzalez8995]

how would a 5.5 oz buffer with quarter and carbine spring work am looking at luth ar kit, angsdast arms, or aero h3 kit

[@joshv06]

I strongly suggest using a dedicated extended 9mm buffer. That way, you wouldn't need so many quarters that would stiffen the spring.

[@jacobgonzalez8995]

@@joshv06 i seen tho in some like the spikes st9x that are too long for the last round bolt hold open feature

[@jacobgonzalez8995]

@@joshv06 also i bought a complete 9 upper at a show with an extended buffer but it only weights 3.5oz

[@MinimalistMotoLife]

Wow, I didn't expect a 10oz buffer would work behind a NFA bolt with standard power factor 9mm, that puts things in perceptive how much mass a blowback action should have. Looks like I will be needing to track down the heaviest buffer made for use with the upcoming 357 sig build for up to and over 200PF, probably the extra power or flat wire spring as well. My wallet already hurts. Thanks for the heads up on NFA firing pins too

[@joshv06]

Yep! They need a lot of weight to delay the blowback. For sure get the KAK buffer!

[@MinimalistMotoLife]

@@joshv06 I was shopping around and the Stern Defense bolt comes in at 1.2oz heavier than the NFA bolt at the same price point, or 1.0oz lighter without the removable weight. Sounds like just the ticket for my build and might be something you would be interested in on future 9mm builds.

[@jeffladd1146]

How much were the spacers in the buffer tube?

[@joshv06]

50 cents

[@jeffladd1146]

Any promo codes?

[@joshv06]

@@jeffladd1146 2 quarters

[@jeffladd1146]

joshv06 free shipping, sweet!! lol

[@traytonjay2670]

Hi, Thank you for this video - nice job and setup. Am seeking any info you may share on this issue. Have built a 9mm AR pistol from miscellaneous parts. It runs, but has some reliability issues after firing - sometimes the extractor seems to miss the casing notch, and the fired casing stays in the chamber. It's inconsistent - sometimes casing extract and other times not - both occurring within a single mag and across various types of rounds. Have bench checked manually with upper only, and the same issue occurs - I may need to push the bolt forward several times, before the extractor catches and pulls the casing back. Same occurs with expended and live rounds. Have removed/cleaned extractor and tried other extractor with same result. Am leaning toward diagnosis of the elusive head space issue - that either the bolt face or barrel rear surface need a few thousandths removed so the extractor can consistently engage the case notch. Interested in any feed back or experience that may relate. Thanks,

[@joshv06]

What kind of barrel, bolt and buffer do you have? Josh

[@jamescreed1303]

Is it normal that the bolt hits the back of the barrel

[@joshv06]

Im sorry what do you mean?

[@markportercrs]

If you had to do it over again would you stick with the same Barrel and BCG? Any other recommendations?

[@joshv06]

I would do the same barrel length. I have the same bolt, but in Nitride for sale here: skidtactical.com/store/skidtactical/skidtactical-glock-ar-9-modular-nitride-bolt/

[@ClearWater7.62]

Hi do I need to run an extra heavy hammer spring?

[@joshv06]

It is preferable not to. Better to run a heavier buffer and a milspec strength spring.

[@ClearWater7.62]

@@joshv06 thanks. I have a 16" barrel, you think a h3 buffer and mil spec spring is ok? My bcg is a kvp or kaw valley, 15.5 oz.

[@drjeffulery]

Built my first home build weapon 12 mos ago - ar9. Bought everything from palometto armory. Went out to fire it and it is shooting a round with trigger pull and release. Haven’t messed with it since because I drop a lot more money very quickly. Was looking at replacing the trigger, buffer tube or the spring as possible solutions. Do you have recommendations which might be the best first options and what products to use? I.e. you recommend a 10.5 oz buffer that I can’t quite understand you when you say the brand.

[@joshv06]

It was a kak 10oz buffer. So the hammer is dropping when you release the trigger? That sounds like a disconnector issue. If it's shooting twice with one trigger pull, sounds like you're getting bolt bounce

[@drjeffulery]

joshv06 getting a discharge on trigger pull and another on releasing trigger. Pretty new to this gun building so not sure what you mean with bolt bounce. Too much movement with bolt? What would cause that? What would you suggest I start with? From the video, Sounds like you have worked through a lot of these issues/bugs already.

[@joshv06]

@@drjeffulery that's definitely a trigger disconnector out of spec. I would get a new trigger group. ALG ACT or ALG QMS. Bolt bounce is when the bolt goes forward with so much force that when it hits the barrel, it bounces back. When it bounces back, the firing pin it it is still going forward and sets off the round. But that's not the issues you're having. You need a new disconnector or trigger group.

[@drjeffulery]

Perfect! I’ll let you know how goes

[@MaxHeadspace9mm]

I have a Ghost upper with a 5.5” barrel and the same bolt as you do. Now I’m shopping for a lower that has last round bolt hold open. What lower do you recommend for my upper?

[@joshv06]

You need one that has the LRBHO mechanism all in the lower (NFA needs the upper and lower). I suggest the PSA LRBHO 9mm lower.

[@MaxHeadspace9mm]

joshv06 Thank you very much. You are very knowledgeable and your video is the best I’ve found on this subject. Building an ar9 is not as easy as building an ar15 I’ve found.

[@coreyrossguitar]

so i have a kak 10 ounce buffer. is it cool to run that with the kak pcc xp buffer spring?

[@Jake-vn2iq]

hey so I just bought an 80% 9mm lower from 80% percent arms. and the 9mm 0din complete upper. its my first 9mm build, but is there a way to modify the lower for last round bolt open? I'm just waiting on parts to ship.

[@joshv06]

Yeah there basically no way you can do that. I would suggest getting a PSA lower when things come back into stock if you want LRBHO

[@Jake-vn2iq]

Haha yeah I figured I realized that after I got it. But thanks for the tip

[@ronskalit8384]

I have a feeding problem with my ATI Milsport. I use ETS and Glock mags but still have the same problem every other round. someone says it could be the mag but as you have mentioned may be to replace with lighter spring and heavier buffer? Please help

[@clopez84]

@joshv06 did you use a standard ar upper receiver or was it specific to a 9mm and not for 556 223?

[@joshv06]

It was a new frontier armory dedicated 9mm upper.

[@clopez84]

@@joshv06 I appreciate the response. Can I use a standard 556 upper receiver? will there be any issues?

[@Freeguy2utube]

Hi i have a Freedoom ornance FX9 9mm carbine .can you list some drop in trigger groups those i use for my gun? Can i use an ar15 trigger drop in trigger group? I m in Canada Thanks

[@joshv06]

Yes you can use ar15 trigger groups. I am sorry but I do not know much about many of them. I just use the Alg ACT

[@thehonestguyreviews4516]

thank you for sharing your experience

[@joshv06]

Sure thing, man!

[@coyotesniper72]

What barrel length would you recommend? I don’t run a suppressor. I run a 10.5 on a 5.56 but was wondering when the powder “burnout” in a 9mm case became a hindrance.

[@leel6429]

I run a 5" on mine. Still quiet.

[@jerrywilson6921]

I bought the 8" CMMG Guard barrel. I figure I can always pin another 8" of supressor to it and get myself right in the eyes of our overlords if I want to use it in rifle form. That's the plan anyway. I thought about cutting mine down but then that option is off the table. You probably don't need more than 5"-6" to get your round up to speed and as accurate as it's going to get. You also have to take into consideration your sight picture, (I enjoy irons more than optics) room for accessories & personal preference. 8.5" of handguard is about as short as I find comfortable. I like to keep my elbow locked. I've put a little thought into this, along with some trial & error. AKA, wasted money and parts in the parts bin.

[@raddad0]

What do you think about Palmetto State armory complete 9mm ARs?

[@brysonw1815]

Rudy A build one Ar9 needs to be quality parts

[@gordo66061]

I think psa uses rebranded new frontier lowers

[@dabigshow6830]

Do you have a parts to help new guy building at 9mm ?

[@stephenfazen2712]

Hi Josh. Great vid - thank you. I've had a 9mm upper for a while, and it works fine (Brigade Firearms) while using my Sylvan Glock Mag converter in the standard Spikes AR lower. I have recently installed the Franklin BFS 3 Binary Trigger into this Spikes lower, and 223/556 works AWESOMELY (400 - 500 rounds per minute). It works fine in semi-auto mode, but when I switch to binary, I am getting a major problem. Something is 'smashing' the lead bullet down into the casing. It looks kinda scary. My BCG has an extra weight in it, so I can use a standard carbine buffer and spring. Any ideas about why this smashing is happening?

[@stephenfazen2712]

My BCG weighs in at 13 oz and my buffer is an H2 standard Carbine sized buffer (using the SBA 3 pistol brace) weighing 4.7 oz.

[@andycraig6905]

Bolt velocity is too high. Needs more weight, try an 8 or 10 ounce buffer. Springs don't hold the bolt closed, they determine how fast it moves. The weight determines how long the action stays closed.

[@snakebite210]

What is a good buffer weight for running suppressed?

[@joshv06]

I really like the kak 10oz heavy buffer. It sounds great suppressed because it's so heavy.

[@brianwilson3816]

I hope you can get this message I'm building one I'm building an AR 9 and it's feeding good now cuz I beat that the back end of it and the other problem is now it's double firing almost like it's going for Auto you got any pointers on that could it be the bolt or what I got a ar-stoner 9 mm bolt carrier group in it if you got any tips maybe I don't know who but right now I mean I got it goin good as far as the the reliability of running but it's still double firing

[@2wheeleddemon999]

Check your sear spring for damage or installed wrong.

[@antoniodgo100]

What’s up man so I just bought a ar-9 from a buddy of mine and the other day I took it to the range and I had several feeding malfunctions i went home and when I was looking at it I noticed the barrel nut was loose I actually took it of with my hand and it came of with the free float hand guard Do you think this might be the issue

[@300whiteout9]

NIGHTRIDER TRUCKER what a buddy

[@mikeswick6473]

would a fostech trigger work on the AR9

[@joshv06]

Not sure tbh :/

[@MrKrash19]

I learned a lot from this video.

[@Ohsaintjoseph]

Is that an extended buffer?

[@joshv06]

Yes. Specifically for 9mm. Made by KAK

[@Ohsaintjoseph]

@@joshv06 nice man. Did you find that the quarters actually helped? I might just buy the spacer that my local gun shop sells that does the same thing.

[@joshv06]

@@Ohsaintjoseph I liked quarters because you're able to fine tune it. If you buy a spacer, you're stuck with the length it is. Plus, quarters are cheap? 🤣

[@Ohsaintjoseph]

@@joshv06 good fuckin point lol. Quarters it is. I’m about to buy the kak buffer. My build is 8”. You think that changes the weight of buffer I should use?

[@jonathanrollins2470]

I'm in the process of getting parts together for a 9mm AR build. What has been your long term opinion on the 10oz buffer + standard spring combo? I am going with a dedicated 9mm Glock mag lower, 5.5" barrel and have ordered a 10oz buffer (at least to start things off). Do you think that weight is appropriate given the short barrel or should I anticipate going lighter? Just trying to collect info as there doesn't seem to be any solid consensus on 9mm AR configs. I'd like to avoid...collecting too many parts in the trial and error process.

[@joshv06]

For sure go with the 10oz buffer and the standard spring. This will slow down the forward bolt velocity and correctly feed the rounds into the the chamber, needed for the higher jump the bullet needs to do. Also, it works great suppressed and unsuppressed. If the weight is too much, KAK sells aluminum and steel buffer weights. But most likely, you will not need them. Best to heave the heaviest weight you can get, than to go lighter.

[@jonathanrollins2470]

joshv06 Cool. Looks like I might be able to get this done in one fell swoop. Thx for the quick reply.

[@joshv06]

Sure think. The KAK 10/11oz buffer has 3 steel weights in it. If it's ever too heavy, you can always go lighter with lighter weights.

[@jimdimitrios1]

i just ran across your video, and maybe you can help me with my build. i double tap periodicly. could i possibly need a heavier buffer?

[@joshv06]

What buffer and spring do you have?

[@jimdimitrios1]

@@joshv06 just a spare psa i had laying around, buffer weighs 5.3 oz. what optics are you running/

[@gboroasis]

I'm having some feed issues on my new ar9 feed.

[@joshv06]

Need more details..

[@gboroasis]

@@joshv06 I built an ar 9mm pistol. Every other shot, it fails to feed in the barrel properly. I'm using aftermarket 30 rd mags. Glock. Just puzzled about what is the fix. I was think the mags.

[@joshv06]

@@gboroasis I would use OEM glock mags. Also, what is your barrel, bolt and buffer?

[@skippythefreak91]

@@gboroasis taccom extreme feed 9mm barrel. it will change your life!

[@william42]

Where did you get the lighter carbine buffer spring?

[@joshv06]

I zip tied a standard carbine spring down to solid height and let it sit for a month. This weakened it a good amount, which is good for the 9mm AR platform.

[@johnsmith-fb5ln]

Is it ok to use a different lower receiver from the upper receiver when building a Glock ar9?

[@joshv06]

Depends. In my case, the upper enables lock back. Other ones like PSA, all of the bolt lock linkage is in the lower, so using any upper you want would be fine

[@johnsmith-fb5ln]

So I got a psa lower it doesn’t have the lrbho. So your saying it should be ok for me to use any upper

[@joshv06]

@@johnsmith-fb5ln yeah it will work with any upper but you won't have lock back

[@johnsmith-fb5ln]

joshv06 ok thanks for the info ,helped me out a lot . Love the videos keep them coming.

[@raddad0]

How much was your set up minus the suppressor?

[@joshv06]

About 700. I don't use this AR9 anymore every since I got an Extar EP9. Review of it on my channel.

[@loonytik25]

I have the PSA AR9(stock) that worked great the first few times at the range. I started having feed issues and thought it was the ammo. You think the KAK Buffer will solve those issues? The ammo is "nosing down" like the hollow point ammo you show here.

[@joshv06]

Loonytik I would highly suggest using a weaker spring or weakening your spring if it's already a standard carbine spring. I would also go with a heavier buffer. I really like the kak 10oz buffer for the money. Doing these two will slow down your feed rate and allow bullets to feed higher than they already are. Also, stick with glock mags or sgm mags. Magpul and eta are all polymer and do not have inner steel which really drags the magazine stack and makes bullets feed low.

[@loonytik25]

I have all Glock mags but, I ordered a KVP 7.5oz buffer to try. You dont think 10oz is a little heavy?

[@edhlavaty6914]

Loonytik I'm finding the lighter spring makes no sense. There are plenty of videos with excellent content and parts that work perfectly when u listen. I used a Kak 5ounce buffer the buffer extension, and a 308 spring and the pistol functions flawlessly. Do your homework

[@joshv06]

You're gonna be getting a lot of bullet setback.

[@edhlavaty6914]

joshv06 From what I found the lighter spring wasn't good for me. Built it exactly like the 9 mm AR specs call for and the firearm runs perfectly. Maybe the Glock Mag set up is different but the only thing I wish I did was use the Kak longer buffer to eliminate the filler block that I used instead.

[@craylonhanson]

Josh I just bought a extar EP9 any suggestions ?

[@joshv06]

The EP9 pretty much overs everything I went for here in this video. I have since sold off my AR9 from this video and use my EP9 as my AR9. I did a review on it in this channel. Just be sure to use OEM Glock mags.

[@davidespinoza1599]

Yeah I suggest you private party sell it to me cuz I'm in Cali and that's the only way I can buy one

[@davidespinoza1599]

Mass Scott

[@818DODGERS818]

David Espinoza try Foxtrot Mike Products FM-9 It’s super reliable shoots everything and you can buy it in CA. I got mine from the Glockstore in San Diego