6mm arc barrel length compare- 14.5” vs 18”

Sure a longer barrel gets more velocity but what does that actually mean for real world down range performance? Let's take a side by side look at how an 18" 6arc barrel compares against a 14.5" barrel out to 1000 yds. In this video we'll take an in depth look at velocity differences, bullet drop at various distances, wind deflection and energy on target.
Instagram: MountainsMulletsMerica
Rifle details
14.5" Setup
- Faxon 14.5" barrel. 1 in 8" twist, carbine length gas system
- Faxon BCG
- Daniel Defense Ris III rail
- BCM upper receiver
- Surefire 762 socom mini suppressor
- Nightforce ATACR F1 4-16 with tremor 3 reticle
18" Setup
- Proof research 18" carbon fiber barrel. 1 in 7.5" twist, rifle length gas system
- Faxon BCG
- Geissele Mk16 URGI rail- 15"
- BCM upper receiver
- Griffin Armament PSR 7 suppressor
- Riton 7 conquer 3-18 scope
Ammo
- Hornady black 105 bthp provided by Ally Munitions
Magazines
- Provided by duramag
00:00 Intro
01:23 Gear Review
07:23 100 yd performance
10:33 18" 275 yds & 380 yds
11:49 14.5" 275 yds & 380 yds
13:00 14.5" 635 yds
13:59 18" 635 yds
15:35 18" 1035 yds
17:35 14.5" 1035 yds
20:17 Shooting review
24:35 What's the actual difference?
26:49 Which barrel length to choose?
28:32 Closing comments

[@LTLC]

Dude... The impacts on the second set of double taps at 1035 are nuts! That was some awesome shooting my dude.

[@MountainsMulletsMerica]

Haha 6arc making it look easy! Such a fun caliber to shoot. Thanks for watching!

[@Persuasian338]

I'm a simple man. I see mullets video. I click.

[@tylerk158]

Simple men unite 🫡

[@jonjaramillo7656]

Simple man here... Mullet's and Johnny's Reloading Bench..... I click no questions asked.... Couldnt pay for this amount of info being given....

[@JohnnyReb-tr2fs]

Wow . That is simple😂

[@tylerk158]

Easily the most underrated guntuber. Keep up the good stuff!

[@MountainsMulletsMerica]

Appreciate the support! Share the word with your buddies!

[@nipsy_lafett]

The accuracy out of an AR platform at that distance is insanely impressive

[@KretinD]

I think the 18" proof uses a rifle+1 gas length. I have a 16" with a rifle length gas system. Such a pleasure to see someone use the 6arc at distance with so many helpful comparisons. My range maxes out at less than 100 yards

[@jbcaptain11]

shoulda got a 300 black then

[@seanoneil277]

100yds, that's .22LR perfection. Get good at marksmanship for very low cost. You could start with irons, then a 3x or 4x scope, a 9x, then a bigger magnification each, as your groups shrink and you are aiming at smaller and smaller things. A lot of people jump right into a full centerfire cartridge when starting with rimfire can dial in your fundamentals very nicely. You can do a lot at 25 yds, at 50 yds, at 100 yds with rimfire. As you get better and better you will see -- the same small inefficiencies play out in rimfire at 50+ yds, as they would in centerfire at 100+.

[@mikestrunk3282]

Rifle length gas tubes are nice! Shoot soft. Just did a 14.1" pin and weld in 5.56 and shoots sub moa with ball ammo. Will do the same with the 6 ARC. Probably 16"

[@velocitydreamer]

I have a build ready and I'm just trying to decide between a 16 and 18 in proof cf. Have you had a chance to shoot out to a thousand? I've arranged nearby that has a thousand, but like the idea of my rifles being at least somewhat maneuverable and lighter.

[@dudeitslogan7367]

Great use of camera work for a one man show! Start reloading 6 ARC and I think you will be very happy with the results. Great job

[@firee2]

I currently have a 6arc with a 24" bartline barrel. That gun shoots sub .5" 10 shot groups at 100 with factory hornady match 108. I know this is on the other side of the spectrum from the short barrel, however it makes for an amazing prs gas gun. Great content, keep up the good work.

[@edouble9894]

You have convinced me that a 6mm arc is going to have to be my next upper. Why shoot 77smk when you can shot a 108 at almost the same speed.

[@jimlerum]

It’s got to be an accurate barrel regardless of the length. Extra FPS is a bonus. Each tool has its place. Know your task, pick your tool. Buy the best tool for the job!👍 Great video. 6 ARC is a good cartridge for a short action option.

[@fordvg]

Great video and the 18” barrel did what I expected it to do. Good shooting.

[@teampyle9835]

That accuracy difference may also be related to suppressor quality too. I'd like to see the accuracy comparison without the cans

[@PatMcMayhem]

This is good analysis. Very helpful.

[@javiersp01]

Another amazing video from you man, thank you !!

[@theaveragereloader7222]

I’m digging the custom sunshade never thought of using an ammo box, I love it. Your killing it man keep the great content coming!!

[@Mike750200]

I'm SO pumped that you're getting the attention and sponsorship that you deserve!!! You've been crushing it for WAYYYY too long to not have sponsors!

[@greatdane3343]

Great presentation and footage and fantastic shooting mate 👍 I'm stoked to see your channel gathering industry support, it is well deserved! Keep up the great work!

[@dobster5819]

Man, that sunshade was beautiful and that reticle on the Riton looked very clean. Your video’s are superb many thanks.

[@lugnut93]

I hope the 6 ARC stays relevant. It’s a great do-it-all round for the AR.

[@seanoneil277]

The increase in commercial loads, varieties of loads, during the past 2 yrs or so suggests it has a place for at least a while. I suspect it may become the most common non-NATO load for the AR 15 platform where distance / wind are factors. A couple years back I was thinking on 6 ARC or 6.5 Grendel or .224 Valkyrie and settled on Grendel as it had the greatest availability of rounds in the commercial market for the best prices/round of the 3 choices. Today the Valkyrie seems off-radar and the ARC on the upswing.

[@toolman9081]

Have you heard about the 6.5 Grendel?

[@lugnut93]

@@toolman9081 of course, but I don’t love the velocities out of a gasser. Starts to get into questionable expansion range quicker.

[@toolman9081]

@lugnut93 I shoot it out of the AR platform. All the data I have on it, stays supersonic out to 900yds. It's a deer slaying machine for me. Unfortunately where I live, I can only stretch it out on the range. But it has taken deer successfully out to 350 yds. It's also been successful on Elk, as the guy that turned me onto the cartridge uses a gasser for Elk hunting.

[@lugnut93]

@@toolman9081Can't argue with your data. There is no doubt 6.5 Grendel is an effective round. But the extra velocity of the 6 ARC gives a little more confidence for expansion at 300+ yards.

[@jeffreydawson4520]

Great video! Lots of useful information and logical conclusions at the end without sounding like the classic “it depends” cop out. Nice shooting too!

[@garrickr5084]

Maybe it’s just me, but this little 6mm ARC (even on a shorty 14.5in barrel) is a freight train fast round. The sounds between each shot and the impacts are incredibly short at those VERY long distances. I’m so used to hearing long delays between shots and impacts on many other platforms I guess. Truly impressed. As usual, thank you for posting.

[@andrewmckinley6571]

Always enjoy your videos

[@Minutes-Mils]

love the improvised sun-shade you got going on the 14.5, I've had to do the same on more than one occasion

[@DoubleXPWeekend]

Great vid man, super informative!

[@derekwilson7946]

Awesome content! Unfortunately Hornday uses a very temp sensitive powder in their 105bthp ammo. Out of my 22" barrel I have seen about 2640fps in 50 deg weather and 2700+ fps in 90 deg weather.

[@oif3vetk9]

Experienced the same thing. Same goes for a lot of the suggested powders for reloading ARC so I've settled for slower velocity and temp stability out of varget.

[@rexhamilton6381]

I had same experience. Over 100 fps difference and maybe 20 degrees difference.

[@Minuteman762]

That’s crazy! I didn’t know temp could affect it so much, do you know if it would be as drastic a change in 5.56 zeroed in 80 degree weather going to 10 degree weather?

[@oif3vetk9]

@@Minuteman762 depends on the powder used. All powders will have velocity variations in extreme temperature swings as you're asking about but some are way worse than others. That's why hunters and competition shooters will do one of two things, they'll either have hot/cold loads or pick the more temperature stable powders they can get. On the average almost nobody will see a temp swing that wild (10 to 80 degrees) in the same day but say start out at 35 degrees and it warms up to 80 degrees that's going to make a heck of a difference at long ranges. Now, for something like a 5.56 carbine shooting out to only 300 yards at a torso sized target, I wouldn't worry about it. It's going to hit. At that point all you need to worry about is "Is this weapon going to function properly?". ;-)

[@KiYoOutdoors]

I love that you be plugging ally, good dudes

[@petehendry4756]

Great video series.

[@s10v8dude]

Loved the video man. I am looking to build a 6arc for my son to hunt and introduce distance shooting. To me, this video really shined the light on differences in budget and higher end barrels. Consistency is just so much better on that proof barrel, and at distance, it really stood out to me. I subscribed.

[@jadoo868]

Awesome video!

[@RaymondMares]

This channel is going places. Glad I got in early!

[@MountainsMulletsMerica]

Glad you’re enjoying it! Share with your buddies!

[@davidpryor7366]

I just left a comment about barrel length on the last video and this one popped up next,, nice! Looking forward to the results.

[@LLB984]

The intro double shot was pretty sick

[@toolman9081]

Love it!! Would also love to hear periodic updates over time on your experience with this cartridge in the AR platform. I have been reading a lot about it and have been seeing a lot of reports about bolt problems, or bolt face cracks with this cartridge.

[@LRRPFco52]

I've been shooting 6.5 Grendel regularly since 2009. I have 7 of them, but have shot 16", 18", and 12" the most. 12" has been shot almost exclusively suppressed with TBAC Ultra 5, with Bootleg Adjustable Gas carrier fully choked. I haven't broken anything but scopes. I have friends who have broken extractors when there was a bad run of extractors, but over thousands of rounds so far, I have yet to break any Grendel bolts or extractors. I have broken 5.56 bolts in torturous high volume sessions. I just changed the bolt and springs, continued shooting.

[@2Aknight762]

I'm not much of a fan of 18" barrels. For 0-500 yards I run 14.5 to 16 inch for a compact light weight rifle. For 500+ yards I want a 20 " barrel to maximize velocity for that flatter trajectory and energy on target. People say 18 is a good compromise but in my opinion you dont get enough benefit of either set up . I'm sure many will disagree in the comments. Or run +P ammo like Hornady Superformance in the shorter barrels to make up for loss in velocity. All that being said, your 18" set up did really well , like that Riton reticle.

[@seanoneil277]

I get your point of "why split the difference" but velocity isn't anything to sneeze at. It's all a weight/balance/maneuverability juggling act, isn't it? Any way you slice it the 6 ARC shoots pretty doggone flat for a pretty good ways, it seems.

[@reedmccleve21]

Thanks for the great content. I'm looking forward to when SOLGW launches the 6mm max for comparison videos.

[@chbales2618]

Building my first 6mm ARC! It’s budget 18” barreled rifle but I’m pretty excited to get it built and see what it does!

[@wildmanjeff42]

nice shooting ! I like a little longer barrel like the 18in. thanks for the video!

[@jamesheldman4659]

Nice video. thank you for the content

[@duaneportwood-kl3sb]

Great video, great information. Subscribed.

[@MountainsMulletsMerica]

Really awesome to hear you enjoyed the video and I really appreciate the support! Lots of fresh content coming so hope you’ll stay tuned and don’t forget to share with your buddies!

[@hebrewhillbilly]

Great info, thank you

[@johnmarken3945]

Nice. Thank you for being responsive after your 14" 6arc vs 5.56 video to getting a more appropriate DMR barrel and giving us data (fps, mrad drop, spread). Thank you also for your other observations. I request further you compare also with Faxon 16" or 18" and let us know the profile. You are not alone in finding that that ammo Hornaday black 105gr BTHP is quite variable. I have been frustrated by that too. Great vid.

[@jasonmorris159]

Already had a build in mind similar to that 18" proof gun. I think I'm going to have to make it happen now

[@806Guns]

My favorite youtuber !

[@TheFlyingFatMan]

Awesome video! Loving the 18" from what I see. I've got a realistic goal for the rifle I've wanted to build since I was 12... even though 6 ARC wasn't around then. 😂

[@kennyfishell8015]

First time watching your videos. Great content

[@MountainsMulletsMerica]

Thank you! Really appreciate you taking the time to stop by and check out my content. Hope you’ll stick around!

[@jimlerum]

Great idea.

[@KiYoOutdoors]

You just plugged Ally munitions, I knew I was gonna like you.. you just earned a sub

[@dcoupard90]

Great video😁

[@nilescoyote4829]

What a well done video, made me miss eastern Montana too. Keep it up and it would be cool to see a comparison between your 18" arc and that new 22 arc down the road. Subscribed.

[@MountainsMulletsMerica]

First off really appreciate you taking the time watch and support the channel! Lots of fresh content in the works so stay tuned. Great point on a 6arc vs 22arc comparison, that’s one that hasn’t even crossed my mind yet. Given the interest in 22arc I bet you’re not the only one asking how the 2 calibers compare side by side

[@robertjackson1407]

Thank you 😊

[@patrickgermain3278]

Referred by TPH, loving the content!

[@MountainsMulletsMerica]

Thanks for stopping by! If you’re into long range shooting I think you’re going to enjoy my content!

[@chadjones7722]

if someone doesn't think the 14.5 is capable they clearly haven't watched your other videos on it. Would love to see more videos with the 108 ELDM's. Disappointed with the faxon group, quality of barrel does matter but still. Definitely pushing the boundary of the 14.5 at 1k but still great to see it land hits. Great video as always.

[@richardwebb371]

I get more knowledge after watching these vids. Absolutely find it fascinating! If sHTF ,this is the guy you want on your team. Your vids hands down are my absolute favorite. You definitely know your stuff!

[@monzahunter]

I have an Odin Works 18in 6 ARC with a rifle +1 gas and love it. Took it out to 1000 last weekend with the intention to double tab but the wind sucked. Hit at 1k but no double!

[@seanoneil277]

Odin Works makes some good barrels. I have a 20" DMR profile 6.5 Grendel, and an 18" 3-Gun profile .223 Wylde. Both easily sub MOA with decent to better ammo, haven't tried handloads for either yet. I've been thinking about that barrel you have. Good to hear it's a shooter too.

[@danielv7964]

Very interesting results with the carbon fiber barrel. I have heard many people talking about groups opening up after about 4 or 5 consecutive rounds. That is why I bought a stainless steel proof barrel instead. I would be interested to see more content on the carbon fiber barrel consistency after heating up, since your barrel seems to be holding groups well

[@rm5902]

I have read carbon barrels are best in bolt guns only !

[@paairmen7458]

Great knowledge keep up the great work and I would like to see you do go from 7.5 to 20 inches in 223 or556 at 500 to 1000

[@brassngas540]

Truly enjoy your videos and what you are doing! Any chance you might consider doing a video on 6mm ARC "point blank zero"/battle zero?

[@TheFlea1987]

Got a 15" 6ARC and the things is one of my favorite rifles to shoot out to distance. Even with my crappy aim I can keep it at MOA. The barrel on it is a Criterion. Only wish ammo wasn't so expensive for it, but Gorilla is coming out with some 6ARC and looking forward to giving that a try.

[@justinwood3054]

I just built a complete 6ARC Wilson Combat upper with their 18 inch barrel. I use in OSS 762TI can. Just got it zeroed, haven’t got it out to distance yet. Great video and content!

[@DiamondsHowImShining]

What kind of MOA do you get?

[@velocitydreamer]

Like the other commenter I am very very interested in knowing your results as far as accuracy and reliability. What MOA are you getting?

[@justinwood3054]

During site in I got one inch with Hornady 108 ELD. A few weeks ago I shot it out to 450 and 600 on 12inch plates. Myself and my friend hit both every shot. I’m very pleased with the accuracy. No problems with liability. I’ve only had time to take it out twice, probably only 40 rounds down range so far.

[@mageman483]

I love your videos

[@bwmalibu1]

Thanks!

[@The340king]

I helped a friend assemble a twenty inch 6mm Creedmoor with a Proof Research full SS barrel. It was crazy accurate. I shot multiple extended single hole groups. The owner shot a 5 shot vertical string of around 3/4 MOA on his fist 5 shots. He was a happy camper. I vouch for the accuracy of the Proof Research barrels.

[@Persuasian338]

I'd really like to see a video side by side best ar15 cal for long range via price per round, terminal performance, and flight ballistics. And thanks to your Eotech Exps 3-4 video, I bought a 5x magnifier, and it pairs nicely with SS109 Norma.

[@hulksmash6476]

Ballistic dummy at the transonic point would be really cool to show power, keep them coming 👍

[@TheLoneRanger745]

At 100yrds. the first 10 warm up 14.5" Factson barrel, not so good 😕. I saw IT do better for you, maybe gettn dirty grooves loosing some twist . Well ...you've shown very well what is possible, outstanding range work as always ❤. Your awesome Buddy

[@mckimmym]

I’d recommend picking up an EABCO 24” to try out. I’ve had good luck with mine and and it’d be interesting to see the speeds for a longer barrel without too much cost.

[@SnapD24]

That was awesome. I like the lighter weight to capability ratio of the 14.5" upper but group size was rough. Got me thinking i might need something better than my Type A barrel. Its not exactly a thick barrel but its not the Gunner profile from Faxon either.

[@randalljeffs7272]

Interesting to see the sonic barrier come into play

[@rascaille3792]

Thanks! 👍🏼🇺🇸

[@deerstrike1050]

Excellent thx

[@AnonYmous-ii4tc]

Second or third time watching this video. Your information and skill are fantastic. Thank you for sharing your knowledge and experience. I'd like to hear more about your history / experience. But... What are you going to do about your "channel" name when you finally grow out of that mullet!?!?

[@websant8299]

good stuff.

[@StudlyDyl]

I built a 20” in 6 ARC… can’t wait to take it out at test it long range.

[@garyday4515]

I really like your videos! No b.s. easy to watch! By the background im guessing you live in the palouse country? Lived in Pendleton growing up.

[@zacherndon9521]

You gotta build out one of those 12.5" from Centurion! I love mine.

[@joshuamcfall1603]

I hope you do a video on the Griffin Blast shield. It would be great to know how well they reduce muzzle flash signature at night!

[@paairmen7458]

And I love your videos

[@bwmalibu1]

Hi and thank you again for sharing your experience strange to see how useful your content is in relation to something I was trying to explain to my friend basically I had to buy two barrels it prove it I find buying custom made barrels has made huge improvements in accuracy I also properly break in my barrel and do thorough cleaning this has improved my accuracy overall Much respect Bill W.

[@MountainsMulletsMerica]

Hey Bill, once again really appreciate you taking the time to watch my videos and support the channel! Lots of new content in the works so hope you'll stay tuned. Can't say I spend much time on the barrel break in side of things as that's been hit or miss for me through the years. Cleaning though is one that I spend a lot of time doing. I went a long time thinking a dirty barrel would shoot just as well as a clean barrel but through the years I've decided that's not the case. I believe some kind of regular barrel cleaning is important to keep a barrel performing as best as possible. I'm thinking it's very possible the large group out of the 14.5" barrel is a result of how dirty it is..... thinking I should clean her up good and then reshoot to see what happens.

[@tonytostada]

Hey where you shooting at, those mountains look similar to the North Oregon pendleton area, or Southern Washington Kennewick area. You have a great channel, been watching you for some time now. I cant wait to see you come out with your own Ammo line in the future.

[@longrangeautist6117]

I bought the same proof CF 18” when they released for my geiselle rifle and honestly I don’t even touch my MK12 uppers anymore. It’s such a good rifle/ammo combination.

[@JGoodZX6R]

Meh, I’m about the opposite. Don’t shoot the 6 arc as much as I expected when I can still shoot 77gr for nearly 1/2 the cost out to my usual 500-700 yards I can get to without driving 2+ hours for 1000 yards.

[@longrangeautist6117]

@@JGoodZX6R I hand load as well as I have plenty of space here in MT so it breathed new life into the AR for me, which is great because I’ve been bored with it for a couple of years now.

[@EssPhour]

What are you running for a bolt carrier group?

[@longrangeautist6117]

@@EssPhour OdinWorks

[@BattleGnome1]

Love how thorough you are with testing with different factors. I would have like to see the 14.5” as a proof or Noveske barrel to see if the grouping at 100 yards improved and to see if the 1035yard shots improved. Also would like to know how you get all these guns for testing?

[@mikestrunk3282]

Nice! Would do a 16" or 14.5" pin and weld. Suppressors are a must anymore

[@trevman187]

Great videos. I'd love to see a comparison of all the hornady factory ammo offerings. I recently just put a 22" 6 arc together and i noticed that even though 103eld 105 bthp and 108 eld all put about the same 3/4 moa group on paper only one was consistent past 1,100 yds but they were all consistent at 1k yds 😂 its been throwing me for a loop . Really curious how the 80grainers will do at distance

[@geoh7349]

I love my proof barrels. they just work. been shooting my 6arc out over 1k on a 20" 2670fps. the best part about it though is how flat it is between 300 and 700.

[@fattigla]

What a bahller move to take negative comments, and turn it into an awesome long range shooting video! Great job!😂

[@MountainsMulletsMerica]

Man I’m just out here trying to keep the people entertained! Comments both positive and negative are how I stay in tune with the audience. Hope this one delivered on your expectations, if so hope you’ll stay tuned for more!

[@stevenbekkering4323]

Great video man! I'm still pretty new to the six arc. I have a fourteen and a half inch carbon wrap proof barrel. You may have said it in your video ( And I just missed it ) but what type of gas block are you running?

[@seanoneil277]

Good stuff, thank you! The bigger drop at longer distance, 3.5" of barrel. Is the Faxon a similar contour even if no carbon sheathing?

[@taylorfreeman5504]

Great stuff! Thanks for the 6 arc content. Do you do anything special when breaking your barrels in?

[@MountainsMulletsMerica]

Nah, just clean the barrel before firing the first rounds and then head to the range. I shoot maybe 50-100 rds the first range session and clean when I get home. I used to do the in depth "break in" procedures you see others doing but never felt like those barrels offered any better performance than the ones I just put rounds through.

[@taylorfreeman5504]

That’s kind of what I was wondering. I have none as nice as that proof barrel. I just clean it and let it loose and seem to get decent results.

[@jimlerum]

The single based powders that work so well in an ARC round dirty a barrel up in 100 rounds. lever Evo and CfE 223 are barrel cleaners after use. Clean and retest and I think you will be surprised

[@JGoodZX6R]

Noticed the same with my 18” BA barrel. One lot of the Hornady 105 was stacking rounds, so ordered 500 rounds of it and this lot is ~1.7 MOA 😐. Although velocity was “only” about 25 fps slower (2575 vs 2600)

[@johnmeyer3163]

Excellent showcase man. Question. I’m in WA as well and looking to get a new upper. Where can I go since importing is out. Point me in a direction? At my own risk of course.

[@CaveLife652]

Cool content. I'd like to see a 6.5 Grendel comparison if you're taking requests.

[@jasonwright6180]

Great Vid. I was wondering what the weight difference is between the 18" 6arc rifle setup vs the 308 rifle setup that you used for the 6arc vs 308 vid?

[@EssPhour]

On average the ARC rifles are 30% lighter, and it is roughly the same for the weight of the bullets. That's per Hornady.

[@slappymcdope]

What is the make/model of the buttstock you are using? I need one... Also, great content. Keep up the good work. Wish I had some wide-open places to do shooting like that!

[@jnichols959]

Love the ideas and execution of your videos! I'd love to figure out where y'all are finding proof carbon barrels for $600 🤤 I agree that a quality short barrel AR can shoot good groups. I have a steel Proof 11.5 223 Wylde that shoots sub-MOA 10 shot groups consistently.

[@user-zx5uz6fb9s]

I just started shooting longer distance, 300+. Id like to know what shooter app you use to help with your MOA calculations. Keep vids coming. Ty

[@dannthorburnn]

In my area my 20” Proof with the H 108ELD is getting 2650-2670 and 9.9 mils of drop at 1000. Interesting to see the drop difference from my rifle to yours.

[@seanoneil277]

Might be shooting conditions -- elevation, humidity -- are a factor.

[@jacmac5058]

Derek Wilson made a comment of this regard, previously. There is a measurement and calculation necessary for long range. Propellent temperature. Just like Derek said, you can see a huge difference with only a few degrees temperature differential. We sent rounds between -30F to +120F. The ballistic calculations wouldn't seem reasonable, but the difference is massive at range

[@jacmac5058]

@derekwilson7946

[@Blueknight1960]

I recently was considering getting a 6mm arc rifle. Then I saw the price of the ammo, took my consideration away quick. I already have a couple of expensive rounds I use, don't need to add another.

[@2acritter4life]

Now i want to swap my Proof Stainless barrel for a carbon barrel.... but yeah 18" is the sweet spot for 6 arc.

[@edgarburlyman738]

Yeah I was like, 14.5? Seems like a 18-22" kind of cartridge to me. I don't think you'd do any worse with Grendel at 1000 outta the 14.5

[@Courtesyflush52]

Personally I've noticed the carbon barrel has a decent bit of POI shift when it starts heating up

[@mitchellfoster]

So enjoyed this video - just exceptional. I've been researching the 6mm ARC for a year now and just finally stumbled on 3M here and am so impressed. What gas block did you put on that Proof barrel? I probably missed this so with apology, what mags do you run for your ARC? Thank you MMM

[@mitchellfoster]

NM on the mags, Mr. lack of detail just need to click a drop down ...would still like to know your gas adjustment set up on the 18" barrel