...I'm never going to get a suppressor?

I want it to be a combination house / vehicle carbine.  Distances would be across-the-room to maybe 50 yards.

I have no experience with the 10.5".  I have an 11.5" barrel.  After coming from 16" and pinned 14.5" barrels, I was pretty happy with how relatively compact it is.  Now I find myself looking at the barrel and wondering if I shouldn't get an inch chopped off (cuz more compact and therefore even better for a house / vehicle carbine! )

Like I said, I have no experience with a 10.5" barrel, so I've been browsing the internet.  This is what I've come away with (and some of it might be incorrect):

PROS:

- A 10.5" barrel is, well, shorter.  More convenient to store and easier to maneuver in tight quarters... like a house or a vehicle.

- There is very little velocity loss dropping from 11.5" to 10.5".  Probably about 60 FPS.

CONS:

- More blast.  More than you would expect for a barrel just 1" shorter.

- You start getting toward the edge of unreliability.  Unless the barrel is overgassed, you need to worry more about ammunition pressure level and cold weather.

- A 10.5" is rougher on parts due to the higher pressure / shorter dwell time vs that of the 11.5".


Reliability is more important to me than having the shorter barrel, so that would seem to indicate the 11.5" barrel.  However, I read a post by a vendor where they said that they had dropped their 11.5" barrel offering because the 10.5" barrel outsold it 100:1 (probably an exaggeration, but still).  I have a hard time believing that if the 10.5" barrel was so unpleasant or hard on parts I wouldn't have seen more complaints about the 10.5" length.  On the other hand, I've read somewhere that supposedly John Noveske considered a barrel of around 12" (or was it 12.5"?) to be the ideal all-around length for a carbine for various technical reasons.

So... do I get my 11.5" chopped to 10.5" or do I leave well enough alone and convince myself that I (uncharacteristically) got it right the first time?

Help me, AR-15 pistol forum, you're my only hope.

Sounds like you answered your own question. Leave it alone and spend the $70 on something else.

Stick with the 11.5" if you're not running a suppressor. I think it's my favorite barrel length under 16" for general use. 10.5" is probably better suited for suppressed guns.

Either is fine.

There is actually a pretty large jump in velocity between 10.3 and 11.5 https://www.ar15.com/archive/topic.html?b=3&f=118&t=509733 and a few other test usually put it around 150-200fps. That is a huge increase for adding only an inch to your total length. Beyond that https://www.ar15.com/forums/t_2_138/174764__Q__Why_BCM_chose_the_11_5_SBR_over_the_10_5_.html BCM makes a fantastic argument for the 11.5 when it comes to dwell time and wear on the firearm.

I'm running a 10.5" but I'm thinking of switching to 11.5 or even 12.5".

Faxon is really nice for the money. Especially if it comes with a pre-pinned gas block.

Looks like KAK also came out with a 12.5" Midlength value barrel.

For me the reduction of in the your face concussion is considerably less with that extra inch with same type muzzle device.  Reliability, both haven't skipped a single beat but the 10.5 doesn't seem quite as smooth as the other .  Size wise, really it's only an inch and for me isn't really that noticeable and I use it for hunting so the extra fps that the added length provides is a bonus.

I just built a 10.5" and a 8.5".  Both run flawless.  Great fun.  Big flames on the 8.5".

By the way good luck finding an in stock 11.5" from either BA or Faxon

Looks like everything is sold out. A sight vendor does have a 12.5" Faxon on sale for a nice price though.

Didn't get it right the first time...

Fix it by picking up an 8" 300blk barrel and some ammo

Thanks for the info and opinions.  I think I'll just leave my 11.5"be.

Hey, you can't look operator when you're standing in front of your bedroom mirror unless you operate operationally.

(By the way, my 11.5" is a Ballistic Advantage. )

I went 10.5 for no other reason than it was the shortest I was willing to go because of pressure and handguard length. I like to have something to reach out on.

I fell for the midlength 16" craze a while back and discovered the smoothest shooting ARs I experienced had more to do with gas port size and weight of the AR than gas port location. All things equal, sure, I can see a 11.5 being smoother, but I love my 10.5 so far. I feel like if I were to do a 11.5, it would be an SBR, and not pistol with blade.

10.5 is fine.
If you build an 11.5, you will still end up building a 10.5".

Now that I have both, I prefer the 11.5".

Dave N

I can dig it.  If you're going to go short, you might as well go as short as is reasonable, right?  At least, that was what I was thinking when I posted this thread for information and opinions.  However, it seems like the benefits of 11.5" make it worthwhile to put up with that whole extra inch (lol).

I haven't had to monkey with my 11.5" Ballistic Advantage setup at all.  It seems to be gassed conservatively (i.e. NOT overgassed).  I stuck an H2 buffer into the pistol that I had left over from a Colt 6720.  From a standing position, it consistently dropped XM193 into about a 1-1/2 foot circle at the 4 o'clock position something like 6 or 8 feet away.   I could probably use a lighter buffer, but I haven't felt the need to try.  It's definitely smoother than the 16" carbine-gassed Colt 6720 that I had.

I know myself well enough to know that you are 100% correct, sir.

I did find a place that had barrels in stock. I got 1 of the last 2 11.5" barrels. I chose Ballistic Advantage

Integrity Arms has 1 left.

I've had a 10.5 and an 11.5..they're extremely close in size. I don't recall one being significantly different than the other.

Installed the 11.5" barrel, Still 1/4" short of the 26" OAL :(

Cmon KAK can't you make the shockwave tube a wee bit longer?

I had plans for this+ Sig Sights



Now I need to throw it on my rifle or just sell it. I guess the law folding adapter would bump me up and make it more portable too.

10.5

what is that thing? I really like their stuff

The grip? Its an MP5K Style vertical grip Sig put out for the MPX.

I went 10.5".

Have heard there's an exponential loss of velocity shorter than that. Also have heard that BCM chose 11.5" minimum on theirs because of reliability concerns due to dwell time.

But tell that to SOCOM, who doesn't adopt fads as quick as they come like the civ side. And they do test stuff pretty well before adopting I would think.

Almost, LMT does the 10.5" and that tells me something. LMT does some hard core R&D, and make very reliable, durable stuff.

If it's going to be short, might as well go as short as justifiable.

Then... realize why you went short, and remember that when you're at the range thinking that it's louder and more concussive than guns with longer barrels.

I have 16", 14.5" and 10.5" guns. Rifles vs PDW type pistols I consider two different types.

Got to shoot my new BA 11.5" Carbine Barrel. I paired it with a Rousch XS4 Rampage Flash Hider

Honestly the muzzle flash and concussion wasn't that bad at all. I was skeptical of the flash hider at first because of how short it is, even shorter than an A2. Adding an extra inch to my barrel and using this was much more bearable over the linear compensator. I'm sure a vortex flash hider would work even better.

I'm also quite happy with my 11.5" barrel in terms of balance and weight. It works for me.