10.5” - 12.5” 5.56 barrel question

CCRBUM

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Apr 9, 2009
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Finally just getting over my disdain for spending $200 on a tax stamp to have a shorter barrel. I wont go down the DI vs piston or the optimal barre length questions as i have read as much as i can find on this. My big this is 1, I plan to get a suppressor for this set up in the future, possibly this year but who know with the way my wife spends money and 2, i realize separating cheap barrels from more quality ones will probably make a difference but as far as spending $300 vs $600 am I going to see THAT big of a performance difference? I want something that will be capable of 1 to 1.5 moa with off the shelf ammo. Realistically I’ll be shooting 55g and 62g ammo for the most part for plinking and then getting quality ammo occasionally for seeing what me and the gun can do. If I’m going to soend the money on a quality barrel i fee like i might as well get a headspace matched bolt with it. CLE has a ready to ship 10.5 for like $515 with the bolt… am i going to see that big of improvement over a DD or a noveske for $300?
 
Sometimes yes. Sometimes no. I’ve seen poverty class barrels shoot fantastic, but it’s a coin toss. Will I happen to get a good one? Will it shoot 2.5 MOA?

Part of what that extra 300 is getting you is confidence/higher percentage odds of getting a good barrel.

SBRs don’t get sold… you’re going to have this thing for decades. Your total cost including tax, suppressior, optic, etc. is going to be 3K or higher…

So do you want a 3K rifle with a poverty barrel for a few decades? Personally that would bug the crap out of me, but I have a friend who would giggle every time he remembered that he saved 10% on the setup by choosing a cheap barrel. So it really depends on your personality.

Keep in mind that high end barrels have good, concentric threads… that’s going to be important when you add your suppressor. A baffle strike to a Surefire SOCOM costs $650 to repair (thanks LMT 🤦‍♂️).
 
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Finally just getting over my disdain for spending $200 on a tax stamp to have a shorter barrel. I wont go down the DI vs piston or the optimal barre length questions as i have read as much as i can find on this. My big this is 1, I plan to get a suppressor for this set up in the future, possibly this year but who know with the way my wife spends money and 2, i realize separating cheap barrels from more quality ones will probably make a difference but as far as spending $300 vs $600 am I going to see THAT big of a performance difference? I want something that will be capable of 1 to 1.5 moa with off the shelf ammo. Realistically I’ll be shooting 55g and 62g ammo for the most part for plinking and then getting quality ammo occasionally for seeing what me and the gun can do. If I’m going to soend the money on a quality barrel i fee like i might as well get a headspace matched bolt with it. CLE has a ready to ship 10.5 for like $515 with the bolt… am i going to see that big of improvement over a DD or a noveske for $300?
1) I would buy a hammer forged chrome lined barrel for an SBR. I currently have a MK18 and the Sig LT with an 11.5" I like the increased durability and am willing to sacrifice some level of accuracy for it. The Sig shoots sub moa, the MK18 hovers around 1.25 to 1.4 MOA depending on ammo with more than 10k rounds through it.

2) Barrel Length and performance. It is roughly a 600 fps in velocity difference between a 10.4 and 20 inch barrel. Here is a chart with two different ammos to compare. https://firearmwiki.com/wiki/5.56_Velocity_by_Barrel_Length.

3) I have never bought a suppressor with the idea that I want to make a rifle as quiet as possible. After owning several, I am really a huge fan of the Surefire SOCOM and I have a mini in ATF limbo currently. I went with the mini on my second because when you seat it on the weapon, it only adds 2.5" of additional length. When shooting M855 it is 1.3 decibels louder than the RC2. To me, the SF Mini is great because you can go 12.5 to 14.5 and still have a very maneuverable rifle while picking up a lot of performance.

4) I agree, people are passionate about different operating systems. I am not going to argue reliability, accuracy, ect. I do want to say that I now prefer piston setups, especially in SBRs. The reason that I like them better is that I experience less gas in the face because of where the gas is vented. My Sig is a pleasure to shoot compared to the MK18. I have read on this forum that various posters have had very good look with PWS, LWRC, LMT, HK.
 
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i realize separating cheap barrels from more quality ones will probably make a difference but as far as spending $300 vs $600 am I going to see THAT big of a performance difference? I want something that will be capable of 1 to 1.5 moa with off the shelf ammo. Realistically I’ll be shooting 55g and 62g ammo for the most part for plinking and then getting quality ammo occasionally for seeing what me and the gun can do. If I’m going to soend the money on a quality barrel i fee like i might as well get a headspace matched bolt with it. CLE has a ready to ship 10.5 for like $515 with the bolt… am i going to see that big of improvement over a DD or a noveske for $300?
IMHO you are wasting your money. Get a decent enough barrel and call it good. These types of setups are designed for close range, at least a 10.5" is. Typically that specific barrel length is 'effective' out to 100 yards or less. That said with my 10.5" I can effectively hit targets beyond 200 yards with little effort using a 1x Aimpoint. The limitation isn't the barrel, it's the optic and the ammo.

Chasing down 'extreme precision' with this kind of rifle goes really against what it's meant for, IE a much lighter and more nimble rifle that can maneuver around obstacles a lot easier.

Also while those machine gun barrels are nice to have, unless you have a full auto again it's a waste of time. If you get a cheaper-ish $100-$150 barrel (mine has a ballistic advantage) about every 12-15,000 rounds you might need to spend another $100-ish bucks on a barrel. That said if you are a high volume shooter it will be worth it to buy once and cry once with a more durable machine gun steel barrel.

Trying to get a matched bolt IMO is just dumb for this type of setup. Again a total waste of time and money to even think about that. You want a good off the shelf regular old BCG and you will be fine.

The intent of a shorter barrel is for quickness, speed, and maneuverability. Trying to make it benchrest level or anything like that is not a good use of brain power.

My 10.5 can easily hold an MOA and it has a Ballistic Advantage barrel. That said, the difference is going to be in the ammo. Also my 10.5 is zeroed at closer distances. Somewhere around 50 yards or in would be about right for this setup.
 
Im leaning towards the barre 346ci recommended. Seems to fit what I’m looking for and i like the mid length gas system. Figured that with a superlative arms adjustable gas block? Then when i get the suppressor i can tune it to run with it and it’ll pretty much live on this upper.
 
Good copy on that. 55s and 62s for plinking and then match grade for seeing what it'll do.


a good barrel should hold under 2 moa with match ammo. i have found speer gold dots to be about 1.5-2 at 100yds in some barrels. of course IMI razor core as well.

i have yet to find a barrel that will shoot under 2moa with cheap m193 type's.

the only "cheap" 62 gr i have found to shoot under 2moa is the winchester usa ready 62gr otm and it was .60/rd
 
I'm my experience a 10.5" barrel in 556 is unbearable without a full size suppressor. A 12.5" with a K can (in my experience) is the same total length, bearable without a suppressor, and quieter with a K can. Ill say the 11.85" PWS falls into the same category as the 12.5" DI barrel. For what you're doing i would absolutely go PWS without question. If you are certain you want DI I would do a Criterion Core at 12.5", adjustable gas block, and radian raptor vented charging handle. The DI will still get dirty at 30x the rate of the piston. I say this having both setups I describe above. Had I purchased the PWS first I wouldn't have bothered with the 12 5" build. I do like it though it simply isn't as good as the PWS with regards to simplicity and cleaning.
 
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Given the cost of your stamp and the cost of ammo, I would suggest buying as good a barrel as possible.

And a better brand barrel tends to shoot more different brands of ammo better in my experience.
I Do the typical accuracy tuning tricks on all my "builds" , they are easy to do, and sure as hell haven't produced any bad side effects. On some of my builds the accuracy improvements have been dramatic.

I think I would go with a 12.5" just for the velocity improvements. And the slightly extended terminal effects.
https://www.ar15.com/forums/ar-15/S...-10-5-11-5-12-5-and-14-5-ALL-DONE-/16-714088/
 
Why is that difficult to believe?
From what I've seen it's a challenge for most guys to Consistently shoot an Honest 5 round 1 inch group, & not cherry pick a 3 round fluke, at 100 yards with a 10.5" barrel semi auto.
Iron sights, Red dot, LPVO, the OP didn't specify ?
The OP states "1 to 1.5 moa with off the shelf ammo", he says 55gr which is usually FMJ,
and then he later changes it to "Match Ammo off the shelf."
With a 20" barrel Quality AR w/ 'good' ammo & shooter ~ Yes. A 10.5" SBR & 55 FMJ don't think so.
^ I agree with Niles Coyote #11^
JMHO
 
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From what I've seen it's a challenge for most guys to Consistently shoot an Honest 5 round 1 inch group, & not cherry pick a 3 round fluke, at 100 yards with a 10.5" barrel semi auto.
Iron sights, Red dot, LPVO, the OP didn't specify ?
The OP states "1 to 1.5 moa with off the shelf ammo", he says 55gr which is usually FMJ,
and then he later changes it to "Match Ammo off the shelf."
With a 20" barrel Quality AR w/ 'good' ammo & shooter ~ Yes. A 10.5" SBR & 55 FMJ don't think so.
^ I agree with Niles Coyote #11^
JMHO
The reference for 55 and 62 as stated was general plinking… i do not expect it to shoot moa. I would however like a barrel that is capable of shooting moa with match ammo as stated… there was no story change, no expectations of bulk ammo being magical, just me being honest with what ill shoot the most and what I expected out of the barrel with better quality match ammo… thank you for your concern.
 
From what I've seen it's a challenge for most guys to Consistently shoot an Honest 5 round 1 inch group, & not cherry pick a 3 round fluke, at 100 yards with a 10.5" barrel semi auto.
Iron sights, Red dot, LPVO, the OP didn't specify ?
The OP states "1 to 1.5 moa with off the shelf ammo", he says 55gr which is usually FMJ,
and then he later changes it to "Match Ammo off the shelf."
With a 20" barrel Quality AR w/ 'good' ammo & shooter ~ Yes. A 10.5" SBR & 55 FMJ don't think so.
^ I agree with Niles Coyote #11^
JMHO
Ammo and optic choices as well as the barrels capability will decide how accurate it is. Length doesn't have anything to do with it. It just so happens that most 10.5"s are relatively inexpensive barrels shooting blaster ammo with a red dot so they aren't thought of as accurate. Again, none of that stuff has anything to do with a barrels length determining its intrinsic accuracy.
 
Im leaning towards the barre 346ci recommended. Seems to fit what I’m looking for and i like the mid length gas system. Figured that with a superlative arms adjustable gas block? Then when i get the suppressor i can tune it to run with it and it’ll pretty much live on this upper.

You dont want mid length gas on a shorty... it likely wont run. you dont have enough dwell time once the bullet passes the gas port...

Probably be ok with a can, but take the can off and IMO all bets are off... unless the gas port is way hogged out.
 
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From what i have researched, as long as the gas port is the proper size it should be fine.

research?

so no real experience.


10.5's with carbine gas is probably similar to 12.5 with a mid. 10.5's arent the easiest guns to keep running reliably. Its a big reason DD did an 11.5" with the Mk18. The extra inch of gas port dwell did a ton to keep the gun running reliably...

My 10.5 runs great with the can and an H2 buffer... Take the can off or throw an H buffer in it and all bets are off. It wont run for shit with a C buffer. Needs the mass to keep the gun locked up for an extra fraction. Short stroke city.
 
You dont want mid length gas on a shorty... it likely wont run. you dont have enough dwell time once the bullet passes the gas port...

Probably be ok with a can, but take the can off and IMO all bets are off... unless the gas port is way hogged out.
Nah. They run great unsuppressed.
 
I know, I've got both, they run all day with no problem at all.
my 10.5 carbine gas runs great with an H2 buffer unsuppressed and good ammo. It will run just about anything with a can on it. It short stroked wolf steel case unsuppressed...thats not uncommon. It short stroked some other brass case cheap stuff(freedom?). I also dont have a hogged out gas port though. It starts to struggle with an H buffer unsuppressed. It wont run for shit with a C buffer, not enough mass to keep it locked up.

All I was trying to tell the OP was that a 12.5 middy IMO isnt the best choice and then to think "ill throw an adjustable gas block on it to tune it"... well you are already working with marginally enough gas to run the gun and then you think you will turn it down further when you put the can on it... I dont personally think thats a good combo.
 
my 10.5 carbine gas runs great with an H2 buffer unsuppressed and good ammo. It will run just about anything with a can on it. It short stroked wolf steel case unsuppressed...thats not uncommon. It short stroked some other brass case cheap stuff(freedom?). I also dont have a hogged out gas port though. It starts to struggle with an H buffer unsuppressed. It wont run for shit with a C buffer, not enough mass to keep it locked up.
I think both my 10.5 and 12.5 gas ports are in the .08x range. Bigger, but not huge. Not even sure what buffer is behind them but they run my hot 77gr load all the way down to my 55gr at 2400fps load great.
 
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Here is a test I did back in 2019 looking for a load that was tuned for my 10.5" Criterion but would still shoot decent in my 18" rock creek. I was using a faster burning powder in hopes to lower the amount of blast in the shorter barrel. Bullets are hornady 62gr bthp's and target dots 1 inch. 10 shot groups.
Screenshot_20230826-151043_Gallery.jpg
 
As long as you don't live in a extremely cold environment it will probably be ok.
I don't know man, I keep hearing that and keep expecting all my rifles that internet lore says won't work in ideal temperatures to really fail in sub 0° weather and they just don't. I haven't been able to test them in really extreme temps because -15° is about as cold as I ever see.
But yes, everything is a tradeoff and will bias your operational window one way or another.
 
Have a 12.5" SBR in 223 Wylde. Used exclusively with a DA Sandman S.

First barrel I had installed was a Criterion hybrid which has a carbine gas length. Shot decent with a 1-8 NX8 when I still had it. Some factory stuff did about 1.25 MOA. Some loads were terrible. Like 5 MOA.

Wanting to try something else I bought a Triarc which has a mid length gas system. Shoots softer, and shot the factory load I wanted to use way better. The Criterion is a decent barrel, nothing wrong with it for the price, I would not hesitate to build with it if I need to build another upper.

I have not done any shooting in the middle of January with it, but being suppressed, I'm sure it would function just fine. I would not hesitate to go 12.5" mid length again. My setup with can is just as long as one of my 16" rifles.

Now, if you want to try that 10.5" down the road you can. If I have my knowledge right, you just need to be able to revert the rifle back to what the stamp says. So keeping a 12.5" barrel around, even if shot out. I also believe you can write the ATF with a letter stating it's new configuration?
I'm not a lawyer, this is the internet. I'm just some backwoods idiot with more stamps than brains.
 
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I don't know man, I keep hearing that and keep expecting all my rifles that internet lore says won't work in ideal temperatures to really fail in sub 0° weather and they just don't. I haven't been able to test them in really extreme temps because -15° is about as cold as I ever see.
But yes, everything is a tradeoff and will bias your operational window one way or another.
I’ve seen quite a few 11.5” guns (properly built) with TDP parts run great in truly extreme cold, as in -30˚C for multi-day high volume courses in the Arctic/Sub Arctic over many years. The same guns ran great in the summer. In fact, I don’t recall any malfs with them.

Chrome-lined chamber and bore, correct gas port, tightly-sealed gas block, tri-bore bolt carrier dims with hard chrome-lined bolt bore, good bolt, buffer, action spring, fed M193 or M855 from anti-tilt USGI or PMAGs, and they go bang. Lubed with CLP or Slip2000 or whatever the Finns were using.

Those courses cover 2005-2016. I’ve always loved 11.5” ARs. 12.5” CLGS and 14.5” run great too with all the correct specs. I really like 12/12.5” as well. A lot of these guns were run naked or suppressed, with big Finnish BR Tuote or Ase Utra cans.

Suomessa%20265_zps072h19hz.jpg


Pretty old-school now, but they just worked. This is one of dozens.

Suomessa%20238_zpskhsyo1h6.jpg


Winter conditions look like this, where you don’t see the ground for 4-5 months, brass just flies into the snow and disappears:

24LahdessaPauliSuomi1_zps16668884.jpg


Real Hks run in extreme cold too. Hk53A3 didn’t seem as controllable as a Colt Commando carbine variant, but the full-size Hk33 is a pussycat to shoot:

bd542f92-f9c7-4254-912a-3f5744539ce6_zpsc2bc7caf1_zps6f247305.jpg
 
I have tons of SBRs and I'll offer up a few universal truths that should help, many already covered here.

1. 12.5 is an overrated length, especially with mid gas. It feels too long indoors and too short outdoors. The mid gas has a short dwell time and lower pressure that lowers it's reliability range. Additionally the velocity gained vs 11.5 is minimal.

2. I strongly recommend 11.5 carbine gas for almost any SBR application, perfect length and reliability. I have 4 of them and only a few of the other lengths.

3. Why do you need so much precision out of an SBR? If that type of accuracy ever came into play you'd be out of your "effective range" anyways so it's just a waste.

4. You'll probably want adjustable gas because these guns tend to have huge gas ports for the lunatics shooting steel case. If you shoot good ammo, get a adjustable gas.

5. 10.5/10.3 is super fun but not practical. It's hard on your parts and has an extremely short effective range. You'll need special, expensive ammo if you want it for defense.

6. I'm not sure why others were treating this like it's a permanent decision. You can SBR one lower and then build 100 different uppers to run on it. Try a few yourself and then you'll come to the same realization that everyone else has, 11.5 is goldilocks.
 
Maybe i need to just order a handful of cheap barrels to screw around with and decide on a length. As long as i keep one thats the length on the form 1 i should be good to go correct?
 
Maybe it would be for you.

Some people require all their guns to be precise and don’t (randomly and artificially) reduce that requirement when they choose a shorter barrel.

LOL...

How many people in this thread have ever used an SBR to shoot a person or an animal? My guess is single digits...

I've shot a single coyote with my SBR in the probably approaching 10k rounds I have put through it. The rest has been on steel. I would guess for 95%+ of SBR owners they are toys. I fall into that category for sure.

If I am going to do something that requires precision it never crosses my mind to grab my SBR... and I have a really nice LMT 10.5" upper on mine...

And again, a short barrel doesnt mean lack of mechanical precision, it simply means low velocity, so "effective range" is generally considered sub 200 yards with almost anything a 5.56 gun can sling. So 2 MOA at 200 yards is 4", thats chest shots...hell thats head shots. Yea you probably arent going to plug a human between the eyes, but a shot to the melon is going to be a disabling shot on a human. But I mean the OP should spend $500+ on a Bartlein cut rifle barrel with a matched bolt to have a 1/2 MOA barrel... its chasing diminishing returns for what an SBR is intended for.

Again, most of these exercises are mental masturbation and it seems in post #40 that the OP is even admitting as such.
 
Well its more of just trying to stay compliant but 🤷‍♂️

ive got a single SBR lower and 3 uppers(300blk, 556, 9mm)...

its simply not an issue.

If the ATF was roaming around screwing with NFA owners it would be all over the internet... ive never heard of it happening, doesnt mean it doesnt, just simply common.
 
ive got a single SBR lower and 3 uppers(300blk, 556, 9mm)...

its simply not an issue.

If the ATF was roaming around screwing with NFA owners it would be all over the internet... ive never heard of it happening, doesnt mean it doesnt, just simply common.
With this administration I would not make any bets. They are busy revoking small ffls licenses at the moment but who knows where it will go