SBR/pistol barrel length???

[Jmeier1981]

SBR/pistol barrel length???

So I'm waiting for an SBR stamp and trying to decide what barrel length to go with...

11.5", 12.5", 13.9"

Is there really that much difference in performance... will the shorter end of this range be neutered in MV and make way more gas and noise or are they all fairly similar
It will be a 223 wylde chamber, most likely always have an OCL Polonium suppressor on it and most likely be shooting 60 soft points if they'll group as I have a case of those. It would be a do all set up with a 1-10× optic that I should always have in the vehicle with me for coyotes or self defense

 

[TonyTheTiger]

I wouldn't SBR a 13.9" just because you don't have to. I've got little 11.5" experience but plenty of 10.5" and 12.5" and the performance difference is significant enough that I think 12.5" is about as short as I would go in 223/5.56.

 

[Deepwoods]

I with on not SBRing a 13.9.

Especially with your optic choice, the 12.5 with its bit-more mv than the shorter options seems a good move. (I have a 12.5 with intermediate gas and its very smooth shooting)

 

[Budrichard]

My SHTF carry is an 11.5” SIG MCX with S&B Dual CC 1-10.

 

[Jmeier1981]

I wouldn't SBR a 13.9" just because you don't have to. I've got little 11.5" experience but plenty of 10.5" and 12.5" and the performance difference is significant enough that I think 12.5" is about as short as I would go in 223/5.56.

Well Ive already got a pile of pistol uppers I can swap on and off as well, just nothing in 223/556 so looking for something to put on it and primarily leave on it for daily carry use. But I want it to still have enough velocity and accuracy to shoot a coyote at 250ish yards without holding 6' over it.
I mean I've got a 9" 450bm with a 1-6× that will group as well at 100yds as my 20" 450bm with a 2-12× on it and only be 200fps slower but I've got very little 223 experience.
I'm also kind of worried that going too short will also be way more gassy and loud... give got an 18" with a suppressor that's very pleasant to shoot, don't really want to lose that and muzzle velocity/accuracy by going too short.
So basically looking fir a goldie locks length for accuracy/MV/gas/sound... overall length between those 3 lengths isn't enough to bother me

 

[HD1911]

11.5” or 12.5” gets my vote

 

[alamo5000]

SBR/pistol barrel length???

So I'm waiting for an SBR stamp and trying to decide what barrel length to go with...

11.5", 12.5", 13.9"

Is there really that much difference in performance... will the shorter end of this range be neutered in MV and make way more gas and noise or are they all fairly similar
It will be a 223 wylde chamber, most likely always have an OCL Polonium suppressor on it and most likely be shooting 60 soft points if they'll group as I have a case of those. It would be a do all set up with a 1-10× optic that I should always have in the vehicle with me for coyotes or self defense

A 10x on a shorties???

As for barrel length it depends. With an 11.5 that is generally accepted as having the least finicky time running a variety of ammo, particularly factory ammo.

That said mine are 10.5 and once set up I've never had a problem. People do say that the shorter you go the shorter the lifespan of some of the upper components. I've never worn anything out myself though.

Accuracy is not a function of length. Extra length adds velocity, which in turn adds to "effect range", whatever that means to you.

If you are a reloader (as I am) you can tailor the ammo to do what you need it to do (within reason).

Generally speaking short barrels are "effective" per those 'official' and semi official standards out to about 100 yards or within. Keep in mind this is assuming two legged critters as the standard. For small critters you can go farther. A lot farther, of course depending on your choice of bullet and possibly other components. For example I would assume a thin jacket varmint type bullet would be better than something with a thick FMJ when talking about terminal ballistics on something relatively small.

 

[LRRPF52]

This barrel length probably has the highest body count of all 5.56 carbines and rifles in history:

 

[Tictacticaltimmy]

Since your putting a 1-10 on it I think 12.5 makes the most sense. 11.5 is also just fine... If its really gonna be ALWAYS suppressed I think a 12.5 middy wins out as it will be real nice to shoot

 

[LRRPF52]

It would be a do all set up with a 1-10× optic that I should always have in the vehicle with me for coyotes or self defense.

If another caliber allowed you to predictably take coyotes out at farther distances, would you consider it?

You can do 10.5” to 12.5” in some of the High Performance Intermediate Cartridges and smoke any 5.56, no matter what barrel length the 5.56 is shot from.

Terminal performance on 2-legged will be better as well.

 

[rlsmith1]

Another vote for 12.5" here too.

I've got a midlength 12.5" and I wouldn't want to shoot anything shorter unsuppressed anyway and this one stays suppressed unless I'm at the range and just want to make noise haha

 

[Jmeier1981]

If another caliber allowed you to predictably take coyotes out at farther distances, would you consider it?

You can do 10.5” to 12.5” in some of the High Performance Intermediate Cartridges and smoke any 5.56, no matter what barrel length the 5.56 is shot from.

Terminal performance on 2-legged will be better as well.

Other calibers such as???

I'm probably stuck on the 223 wylde for this one... I've got other uppers like 7.62x39, 300BLK, 450BM that I can use from time to time but for cost of ammo, the fact that I've already got a bunch of it and the suppressor that I want to use with it would only work up to 6mm anyways

 

[Jmeier1981]

Another vote for 12.5" here too.

I've got a midlength 12.5" and I wouldn't want to shoot anything shorter unsuppressed anyway and this one stays suppressed unless I'm at the range and just want to make noise haha

How is a 12.5 suppressed... is it gassy as shit? I'm guessing it's going to be louder than my 18" suppressed but no idea how much difference there would be... never been around a suppressed SBR/pistol, always 18" or longer hunting rifle set ups

 

[rlsmith1]

How is a 12.5 suppressed... is it gassy as shit? I'm guessing it's going to be louder than my 18" suppressed but no idea how much difference there would be... never been around a suppressed SBR/pistol, always 18" or longer hunting rifle set ups

It's not terrible, and mine is midlength so it helps with back pressure a little. Still runs fine unsuppressed but might have issues when really dirty in extreme cold. I've got a Sandman S and F1 6" can I use and both are fine. Not quiet by any means but no concussion and super comfortable with ears on top of that.

18" vs 12.5" or other short barrels... You're fighting 2 things: shorter barrel so higher pressure for suppressor to suppress (ie louder), and the noice is closer to the shooter with the louder barrel. I've only noticed this when shooting with no ear pro, if you're using ear pro then it's pretty much all the same unless maybe shooting in a structure or something where concussion has no where to go

 

[John?]

I have a 10.5 and would not do that again. When I replace barrel it will be 12.5 for 5.56 and 6.5grendel.

 

[LRRPF52]

Other calibers such as???

I'm probably stuck on the 223 wylde for this one... I've got other uppers like 7.62x39, 300BLK, 450BM that I can use from time to time but for cost of ammo, the fact that I've already got a bunch of it and the suppressor that I want to use with it would only work up to 6mm anyways

You could do 224 Valkyrie, 22 ARC, or 6mm ARC if you’re limited to a 6mm can.

I’ve been shooting 5.56 in high volume since 1987, but it just doesn’t move my meter anymore. I still have a ton of them, stacks of ammo, mags, etc., but I just enjoy the higher performance of Grendel, since it has 34-35gr case capacity and can spit bullets of substantial weight from the AR-15, while still not disrupting the sight picture much.

 

[smcfarland]

If I could only have one rifle, it would be my 11.5 SBR MCX Virtus. Surefire Mini suppressor on it, a little gassy and loud but perfect maneuverability. Have bounced between different optics but a 1-6 LPVO makes consistent hits out to 600m with mk262 (once get a decent wind call).

 

[LRRPF52]

If I could only have one, it would be my 12” Grendel suppressed.

It does what none of the 5.56 blasters can at any range, and performs more like a .308 at distance, only with easy sight picture tracking/self-spotting. I’ve been shooting it every range trip and course since 2017. Very fun little gun that does things you would have to see to believe at distance. Hits the steel loud.

 

[John?]

If I could only have one, it would be my 12” Grendel suppressed.

It does what none of the 5.56 blasters can at any range, and performs more like a .308 at distance, only with easy sight picture tracking/self-spotting. I’ve been shooting it every range trip and course since 2017. Very fun little gun that does things you would have to see to believe at distance. Hits the steel loud.

@LRRPF52

I like the cut of your jib. I’ve been using a 6.5G bolt gun for the reasons your cite. The Hornady SST does the job on predators. I am very tempted to assemble an AR upper for Grendel. Concern about bolt durability is the main thing holding me back. A short carbine is really handy around the homestead.

 

[bfoosh006]

Great thread on 10.5", 11.5", 12.5" and 14.5" barrel velocities.

Slightly dated... but well worth the read


https://www.ar15.com/forums/ar-15/S...-10-5-11-5-12-5-and-14-5-ALL-DONE-/16-714088/

 

[LRRPF52]

@LRRPF52

I like the cut of your jib. I’ve been using a 6.5G bolt gun for the reasons your cite. The Hornady SST does the job on predators. I am very tempted to assemble an AR upper for Grendel. Concern about bolt durability is the main thing holding me back. A short carbine is really handy around the homestead.

I’ve been shooting Grendel in pretty significant volume since 2009, starting with a 16” MLGS AA barrel/bolt combo. Then went to 17.6” Lilja MLGS in a really lightweight build, that still hammers out at 1000yds.

I haven’t broken anything but scopes, which were discontinued models that had reticles I really liked and rolled the dice on, hoping I would be a special snowflake.

I use Rexus bolts now, but have a ton of trigger time on the older AA, Maxim, and Monster Logo group buy bolts too. You would think I would have broken a bolt on the 12” CLGS suppressed by now. I even loan that one out in DM courses where guys have abused it with Wolf.

6.5 Grendel is what the AR-15 should have been chambered in from the start, and we could expand the chamberings off of that instead of .222 Remington.

Try the 100gr ELD-VT from Hornady if you want a great predator round in Grendel. It’s way flat-shooting, fast, easy to hit with.

 

[John?]

@LRRPF52

Thanks. That is helpful.

 

[B4forever]

My primary work gun is a 11.5” BCM w/Sig SLX556 suppressor. Optic is a EXPS3 w/G33 magnifier. I absolutely love this setup and wouldn’t change anything. Running the number on 64gr bonded 556 I should get expansion out to around 275yds. With your optic setup I would tend to favor the 12.5” setup, especially if you won’t spend a lot of time inside of structures or vehicles.

 

[346ci]

12.5” mid gas .223 and 6.8 here, both suppressed.

 

[LRRPF52]

12.5” mid gas .223 and 6.8 here, both suppressed.

What speeds are you getting with the 12” 6.8?

 

[hlee]

Did someone say 12.5” suppressed 6.5 Grendel?

 

[JWG]

How is a 12.5 suppressed... is it gassy as shit? I'm guessing it's going to be louder than my 18" suppressed but no idea how much difference there would be... never been around a suppressed SBR/pistol, always 18" or longer hunting rifle set ups

Nothing is "gassy as shit" if you're using a modern flow through suppressor, which, for health reasons as well as reliability and performance, I think are the way to go.

 

[JWG]

My primary work gun is a 11.5” BCM w/Sig SLX556 suppressor. Optic is a EXPS3 w/G33 magnifier. I absolutely love this setup and wouldn’t change anything. Running the number on 64gr bonded 556 I should get expansion out to around 275yds. With your optic setup I would tend to favor the 12.5” setup, especially if you won’t spend a lot of time inside of structures or vehicles.

Since you say "work", I presume you mean the new Federal LE stuff or the older RA556B. The RA556B is shaped similar to a dump truck, but the new federal stuff is a bit better. I average around 2660fps with it from my 11.5. However, 275 yards is pushing it, as I believe that round has a 2000-2200fps floor, and a BC G1 in the mid to low .2s. Even presuming 0.25 G1, that puts you at under 1800fps by 275y. At 175 yards, you're running 2000fps. The last testing I saw on LE223T3 seems to indicate 125-150m will be the "I am sure it will work" range, and 175-200 is "man...maybe?"

I think people tend to err on the side of all planets aligning when it comes to PAD ranges in 5.56 projectiles. I'd prefer to err the other direction. I'd draw my line at 125m for that round regarding "this WILL perform". If you want more range, 62gr Dual Performance or 70gr TSX will extend that confidence level to 300 and 225 yards, respectively.

By perform, I mean you recover the round and look at it and say "Damn! Just like in the brochures" not "yeah, it did something, see the nose, there?"

An example is this 70gr TSX I recovered from shooting a white-tail lengthwise at about 100 yards using my 11.5. Predicted impact velocity was 2350fps:

 

[MSTN]

According to Craddock Precision, an 11.3" .223 Wylde with carbine +1" gas system gives velocities equal to or greater than a 12.5" .223 Wylde with mid-length gas system.

 

[JWG]

According to Craddock Precision, an 11.3" .223 Wylde with carbine +1" gas system gives velocities equal to or greater than a 12.5" .223 Wylde with mid-length gas system.

I'm guessing it depends on powder, loading, bullet weight, pressure curves, and all that jazz. Might for one specific loading.

 

[B4forever]

Since you say "work", I presume you mean the new Federal LE stuff or the older RA556B. The RA556B is shaped similar to a dump truck, but the new federal stuff is a bit better. I average around 2660fps with it from my 11.5. However, 275 yards is pushing it, as I believe that round has a 2000-2200fps floor, and a BC G1 in the mid to low .2s. Even presuming 0.25 G1, that puts you at under 1800fps by 275y. At 175 yards, you're running 2000fps. The last testing I saw on LE223T3 seems to indicate 125-150m will be the "I am sure it will work" range, and 175-200 is "man...maybe?"

I think people tend to err on the side of all planets aligning when it comes to PAD ranges in 5.56 projectiles. I'd prefer to err the other direction. I'd draw my line at 125m for that round regarding "this WILL perform". If you want more range, 62gr Dual Performance or 70gr TSX will extend that confidence level to 300 and 225 yards, respectively.

By perform, I mean you recover the round and look at it and say "Damn! Just like in the brochures" not "yeah, it did something, see the nose, there?"

An example is this 70gr TSX I recovered from shooting a white-tail lengthwise at about 100 yards using my 11.5. Predicted impact velocity was 2350fps:
View attachment 8573382
View attachment 8573384
View attachment 8573383

Yes, RA556B. We also issue Federals LE223T3 62gr bonded load. The Winchester is loaded with a 64gr Nosler and they quote a .231 G1 BC and a 1800fps minimum impact velocity for expansion. My chrono data is on my work computer, but if I recall correctly it was around 2600fps. At my elevation (3600ft) I drop below 1800fps just past 250yds. But yes, this is assuming the best case scenario for the quoted numbers.

 

[346ci]

What speeds are you getting with the 12” 6.8?

I get 2480 with the 120gr SST factory load. I'd have to dig out my reload info, haven't reloaded for it in a while.

 

[JWG]

Yes, RA556B. We also issue Federals LE223T3 62gr bonded load. The Winchester is loaded with a 64gr Nosler and they quote a .231 G1 BC and a 1800fps minimum impact velocity for expansion. My chrono data is on my work computer, but if I recall correctly it was around 2600fps. At my elevation (3600ft) I drop below 1800fps just past 250yds. But yes, this is assuming the best case scenario for the quoted numbers.

A lot of companies are FOS. That Nosler bullet likes about 2000-2100fps minimum, and the actual BC is around 0.18 G1. Companies just publish whatever they want, and people believe it until they aren't on target or are far lower than they think they should be, and bullets don't open when they should have, and so on.

This isn't agency data in the video below, but it is open-source and I can freely share it, and it should be an eye-opener that...maybe there's an issue with that 250 yard efficacy you have derived from the data handed to you by Nosler/Winchester:


Here is another open source:


Like I was saying, 2000-2100fps is going to be bare minimum "It did something at least..." for this bullet. And it's going to arrive at that velocity a lot closer to the muzzle than Winchester/Nosler is claiming.

 

[hlee]

It’s almost 2025, only tic toc ‘tards still film in “potato.”

 

[Obi-WanKannoli]

11.5 carbine or 12.5 mid, done. Pick one.

 

[MSTN]

Here's more on the Craddock DMR-LE idea with Bartlein 11.3" and carbine +1 gas system. A good article on the subject written a few years ago by two men still in the arena:

https://zerotheory.org/the-le-dmr-concept/

 

[JWG]

Here's more on the Craddock DMR-LE idea with Bartlein 11.3" and carbine +1 gas system. A good article on the subject written a few years ago by two men still in the arena:

https://zerotheory.org/the-le-dmr-concept/

A properly chambered Bartlein barrel do be like that.

 

[alamo5000]

Other calibers such as???

A 12.5 in 6ARC is tempting for me. That type of setup is (at least on paper) insane.

 

[alamo5000]

I have a 10.5 and would not do that again.

Wondering why? I love my 10.5. At least for me, I make my own ammo and have a great suppressor. Mine is tuned exactly how I like it.

That said I don't have 30 SBRs (yet) to try everything else out. Tempted, yes, but not yet.

 

[fanninland]

I get 2480 with the 120gr SST factory load. I'd have to dig out my reload info, haven't reloaded for it in a while.

It’s been a while since I chrono’d it but FWIW that’s what I got with 12.5” 6.8 suppressed/factory 120SST. Generally used at night inside 150 yds but on occasion enjoyed success on hogs/yotes out to 325 yds.

 

[Steel+Killer]

Just curious when you SBR a rifle with the ATF do you have to state exactly what the barrel length is? Since the lower is actually going to be the serialized part would it be illegal to change the length of the barrel after you receive the tax stamp? Wouldn't it be similar to how if you have a legal full auto lower you can use it with different uppers?

Sorry not trying to derail the thread.

 

[MaximusDecimusMeidius]

a mid length gas setup does run significantly smoother than a carbine length gas

you could probably get away with a 12.5" midlength with the extra dwell length if it will be used 100% suppressed

12.5" mid might be iffy for non suppressed depending on a lot of variables

11.5" is the easy button but a little gassier

 

[Gtscotty]

I really like my 12.5 mid gas 5.56 and 6 ARC, not too enthused with my 10.5, but haven't put much effort into it since getting the 12.5s.

Out of the 5.56 with AAC ammo in the new barrel my velocities were:

77gr OTM: ~2,560 fps
75gr Saber BT: ~2,520 fps
62gr Saber BT: ~2,640 fps

Seemed pretty decent for such a handy package.

 

[TonyTheTiger]

12.5" mid might be iffy for non suppressed depending on a lot of variables

I assumed as such when I bought mine. I can't get it to be finicky no matter what I do. All vanilla reciprocating components, no adjustable anything, various ammo types at widely varying pressures and it just keeps going. Some friends were impressed by it, bought their own and have had the same experience.

 

[TonyTheTiger]

According to Craddock Precision, an 11.3" .223 Wylde with carbine +1" gas system gives velocities equal to or greater than a 12.5" .223 Wylde with mid-length gas system.

I absolutely believe a particular 11.3" barrel could match the velocities of another 12.5" barrel. I've got a bunch of 14.5" barrels that are faster than the average 16". I've got some 16" barrels faster than the average 18". And I've got slower than average barrels too.

But I hope they're not implying the gas system length is the reason for it. It's almost 2025, chronographs and adjustable gas blocks are so common that anyone with 5 minutes to spare can prove that the difference in velocity from wide open gas to shut off is almost imperceptible and by that logic the velocity difference between gas systems an inch apart from each other is basically non existent.

 

[MSTN]

I am the original 12.5" 5.56 fanboy, I do believe. John Noveske made a bunch of them for me starting almost 20 years ago. With John's match chamber, they were as fast or faster than a new LMT 14.5" CL barrel with a NATO chamber.

I'm not qualified to speak for Craddock , but the message I got from him was his 11.3" Bartlein with carbine +1" gas system produced similar velocities to an otherwise identical 12.5" Bartlein with mid-length gas system. Reason given: With the 12.5", a lot of gas had to be dumped into the mid-length gas port to compensate for the short dwell time. Less gas was required to run the 11.3" gun. That gas not used produced velocity.

I don't need to add these Craddock produced Bartlein barrels are amazingly accurate.

 

[TonyTheTiger]

I'm not qualified to speak for Craddock , but the message I got from him was his 11.3" Bartlein with carbine +1" gas system produced similar velocities to an otherwise identical 12.5" Bartlein with mid-length gas system. Reason given: With the 12.5", a lot of gas had to be dumped into the mid-length gas port to compensate for the short dwell time. Less gas was required to run the 11.3" gun. That gas not used produced velocity.

I get the idea behind the theory, but back when I tested it, in multiple barrel lengths including a 12.5" mid, the difference between a wide open to completely shut gas block was always less than 20fps average. So less than the ES of all but very few types of ammo.
I actually did the test to settle this very argument with a buddy. Made sure he was there to see it too. Very few people that talk about gas system length vs. velocity seem to have done anything more than compare one barrel against another.

 

[MSTN]

That sounds like an interesting test.

Now, I need Craddock to build me a couple more barrels to run something similar.

I do wish there were more 11.5" forend choices to use with 12.5" builds. I've got an ancient one I'm using on my 12.5" 6ARC. I can't even recall who made it.

 

[TonyTheTiger]

Looks like a Mega?

 

[MSTN]

It's got the same wedge-lock thing going on.

I had to Google a while - Hodge Defense forend.