Anyone want to talk AR shorties?

[ShortShooter1908]

I realize this is at the opposite end of the spectrum of what this forum is about and what we all probably spend most of our time and money on but I have got to think that there are at least a pistol or SBR in a few safes and I trust this forum.

Looking at 11.5" uppers. Build or but I haven't decided. I'm looking at the 11.5" because I have heard talk of dwell time issues with the 10.3"& the 10.5". Not crazy about the 12.5" because I am planning on using a Law Folder on this set up and that adds an inch. Obviously with the short barrel and the folder I am prioritising the compactness. I also don't want a gun that is going to have cycling issues.
Experiences? Thoughts?
TIA

 

[SLG]

I've run 11.5" at work for the past 10 years. So has everyone I work with. I'm not a fan of short AR's, but the 11.5 works pretty well.

 

[knuckleballz]

I've always thought with a short barrel build of that length 300 blackout would be the easiest to make function with the short gas length. That short barrel length under 12 inches would be the most efficient with 300 blackout. I guess it comes down to what you want to do with it. What caliber do you want to use?

 

[SLG]

300blk is optimized in a 9" barrel. Best choice in a shorty, hands down. I (wrongly?) assumed the OP was asking about 5.56. I like 9" blk very much. I prefer 14.5" 5.56, but our 11.5" do work.

 

[flyer]

The Law folder is pretty cool. I would build it on a pistol or "other" lower or even build it from an 80% and use a pistol brace to avoid NFA hassles.

Don't add a VFG, that would make an AOW which is another NFA hassle.

.300 Blackout could be cool, especially if you spent your NFA hassles on a good .30 cal can.

If you stick with 5.56, go with a 1 in 7" barrel for a little more stability at the lower MV.

 

[ShortShooter1908]

I've always thought with a short barrel build of that length 300 blackout would be the easiest to make function with the short gas length. That short barrel length under 12 inches would be the most efficient with 300 blackout. I guess it comes down to what you want to do with it. What caliber do you want to use?

556. I have a 16" and a 20" already in 223 Wylde.

 

[ShortShooter1908]

The Law folder is pretty cool. I would build it on a pistol or "other" lower or even build it from an 80% and use a pistol brace to avoid NFA hassles.

Don't add a VFG, that would make an AOW which is another NFA hassle.

.300 Blackout could be cool, especially if you spent your NFA hassles on a good .30 cal can.

If you stick with 5.56, go with a 1 in 7" barrel for a little more stability at the lower MV.

Thought was to use the SBA3.

From the internet (yeah I know), I heard that if OAL is 26"+ everything changes. I have a call into my local ATF so I don't screw up.

 

[flyer]

You could be right about the 26" thing but you might need a 16" barrel too, I think Franklin Arms might have an ATF letter for a similarly configured "other".

 

[trob_205]

I would say Daniels Defense put a blemish on the 10.3” and 10.5” BBLs. Their gas port was huge and they were highly overgassed. I would feel very confident in a factory LMT 10.5” upper. I have a 11.5” colt barrel that was cut down from 16”. Didn’t touch the gas port because I didn’t have too. For 10.5” guns I would try to get as close as possible to true MK18 specs. If your going 11.5” then I wouldn’t sweat it too much. I wouldn’t shy away from 10.5” tho. Just make sure you’re buying the right 10.5”.

 

[VegasHKShooter]

I have both a 10.3 DD upper (their version of a MK18) and I built an 11.5 BCM upper. The 11.5 is MUCH nicer to shoot. I find myself reaching for that much more often than the MK18. The 11.5 is less blast, less obnoxious, overall nicer to shoot.
It may be that the gas port is the size of a manhole cover on the 10.3. I could easily install an adjustable gas block on the DD, I just don’t shoot either of them enough to worry about it. 90% of my AR work anymore is MK12 or DMR style shooting. More NightForce 1-8 than Aimpoint T1.

 

[ShortShooter1908]

and I built an 11.5 BCM upper. /QUOTE]

I am assuming that you mean this is a BCM barrel with various other parts. Do you remember which gas block you went with?

 

[VegasHKShooter]

The gas block on that particular upper is just a BCM low profile gas block. I’m running it under a KMR rail.
I really enjoy that rifle. Much more so than the DD MK18. Seems like, as with anything in life, that extra inch makes all the difference. ?

 

[Crews]

Primary SBR use for me is hunting and personal defense. With that being said, I wasn't crazy about 556 for either one of those purposes. It was ridiculously obnoxious, even with a suppressor on it.

For a PDW, I don't carry it around with a can. The 10.5" 556 was so incredibly loud that using it in a self defense situation without hearing protection was just inconceivable. Now, I have a 8" 300BLK upper. Supersonics do better out of a shorter barrel, plenty of energy on target, is 100% reliable, and the muzzle blast is much more comfortable (relatively speaking.) With a LAW side folder, mine disappears in any normal backpack that's 18" tall.

For hunting and general use, I really like a 11-12.5" 6.8SPC or 6.5 Grendel. Much more effective on living things, plenty of energy and accuracy out to 300 yards. Plus, Grendel ammo for practice and training can be had for cheap!

 

[shoobe01]

As stated above, people run issued guns as short as 10.5 all day long that work great. I've been told 11.5 on up is the sweet spot. I have a 12.5 5.56 upper (BCM) which I love. Have had two muzzle devices on it now (awaiting a suppressor) and I have had no issues, and have not had complaints from friends shooting it, or next to it. It does seem to be a tidge less accurate to 300 than my 16" 5.56 gun, but different guns are different; I may simply have a very good 16" gun, or the slight differences in the sight setup is enough with my bad eyes.

I also have a 10.5" .300 BLK, because it is supposedly designed for 9-10" barrels, and it works very neatly out of that. Even supersonics are quite tame at that length.

 

[RyanScott]

On ARs longer barrels are better in every way except weight and length. That said I favor 11.5-12.5 and if the law made no distinctions I’d have a pair of 12.5s and no other 5.56x45 rifles

 

[ShortShooter1908]

So I am definitely focusing in on the 11.5". Is BCM the favorite flavor at that length?

 

[TanktheFrank]

I run a 12.5 in pistol configuration. Shockwave blade, vfg, and oal of 27.5 make it a firearm. In essence, a pistol with no stock (brace is a brace), meant to be fired with 2 hands (vfg) with a length over 26" means it is not a pistol or a rifle. It is a firearm.

 

[ShortShooter1908]

I run a 12.5 in pistol configuration. Shockwave blade, vfg, and oal of 27.5 make it a firearm. In essence, a pistol with no stock (brace is a brace), meant to be fired with 2 hands (vfg) with a length over 26" means it is not a pistol or a rifle. It is a firearm.

Yeah. ATF finally got back to me. They said end of bare muzzle or P&W device to the end of buffer tube. I figured SBA3 with law folder and a 11.5" I should be good for a vfg.

 

[SLG]

BCM is hard to beat for out of the box goodness. Colt also makes a great 11.5"

 

[mgrs]

I think 11.5" is about the perfect SBR length if you do not count 14.5" guns. The chrono numbers are not as bad as a 10.3 and the extra 1.3" is evident but not significant.

I have also had better luck with 11.5" (unsure of port size, DD CHF barrel) than 10.3" (Colt and newer DD, .070 ports) especially suppressed.

I have had a DD CHF 11.5" barrel with pinned block for about 4500 rounds, and it has been fantastic, suppressed with a gassy gemtech or less gassy Surefire. It will run fine with the surefire and an H buffer, but likes H2 or even H3 suppressed with MK262-velocity 77gr ammunition.

I'd also say that, looking at it with a bore scope, the CHF DD barrel is beast. Like many non-FN CHF barrels, it looks pretty ugly under the scope but wears really hard. Does not show heat cracking or port wear as quick as Colt tubes under similar round count and abuse.

It's an honest 2" with 77gr reloads in 5 round groups at 100 yards, which I am really happy with for what it is.

I would say Daniels Defense put a blemish on the 10.3” and 10.5” BBLs. Their gas port was huge and they were highly overgassed. I would feel very confident in a factory LMT 10.5” upper. I have a 11.5” colt barrel that was cut down from 16”. Didn’t touch the gas port because I didn’t have too. For 10.5” guns I would try to get as close as possible to true MK18 specs. If your going 11.5” then I wouldn’t sweat it too much. I wouldn’t shy away from 10.5” tho. Just make sure you’re buying the right 10.5”.

Apparently DD has finally listened, their newer barrels are more appropriately ported.

 

[Badfinger]

I run a .223 @ 10.5" and a .300 BO at 9" and both run great, no issues.

 

[YO_Doc]

I'm running an LMT MRP with a 12" in it. Solid system. Nice thing about the MRP is a slightly longer handguard which I find nice. They also make an 11.5" barrel for it now, I will most likely go with that once this barrel is worn out.

Edit/added
The thing that I like about it is that I can still hit steel in the 400+M range although you do have to listen closely to hear it.

 

[Keyst0ne]

BCM is hard to beat for out of the box goodness. Colt also makes a great 11.5"

KAC's SR-15 CQB upper is also 11.5. One of my favorites, I like it better than my 11.5 BCM for reasons I can't really articulate but I do. Also really like my 12.5" Grendel. Oh and my BCM 12.5 with AEM5.

 

[flyer]

Yeah. ATF finally got back to me. They said end of bare muzzle or P&W device to the end of buffer tube. I figured SBA3 with law folder and a 11.5" I should be good for a vfg.

Be careful with that, some places measure folded...

 

[PBWalsh]

If an AR can’t fire when folded (because of the buffer tube) would that actually matter?

 

[ShortShooter1908]

If an AR can’t fire when folded (because of the buffer tube) would that actually matter?

I can be fired once folded. Manufacturer advises against it. The guy from Sage Dynamics did a review. After 100 cycles, there was some significant wear to certain components.

 

[SLG]

KAC's SR-15 CQB upper is also 11.5. One of my favorites, I like it better than my 11.5 BCM for reasons I can't really articulate but I do. Also really like my 12.5" Grendel. Oh and my BCM 12.5 with AEM5.

I have a KAC 14.5", and it is my favorite AR. .75 moa accurate, very light and handy. Good trigger. What's not to like?

Still, I usually recommend BCM and colt, for various reasons.

 

[JFComfort]

I went with a 10.3” barrel, Spring Co action spring and H3 buffer. The rifle runs well, non-adjustable gas block.

 

[RTH1800]

I have played with the SBR in 5.56 suppressed quite a bit. My expirecnce is that the top end stuff, Colt or KAC will function fine. Others, not so much. The 5.56 is about as loud suppressed as an unsuppressed 18" gun or so it seems. Much louder than a suppressed 18" for sure.

Accuracy is Sub MOA for the better makes with Mk 262 Ammo.

I have also found that the 11.5" barrels simply do not kill well compared to a longer barrel. Very disappointing.

 

[freedom71]

Check out Primary Weapons Systems' shorties, especially the MK111 MOD 2-M in .223 Wylde (11.75 in barrel) and the MK109 MOD 2-M in .300 Blackout (9.75 in barrel). They have piston systems and very high quality workmanship.

I have a PWS .300 BO pistol and am building a PWS .300 BO SBR. I couldn't be more pleased with their quality, balance, weight, and accuracy.

Also, if you're looking for a great brace for a pistol, check out Gear Head Works Tailhook Mod 2.

 

[ShortShooter1908]

I have also found that the 11.5" barrels simply do not kill well compared to a longer barrel. Very disappointing.

-Longer meaning 12.5"? 14.5"? 18"? 20"?
-What kind of projectiles were you using?
-What range were you having poor performance?
Not questioning your experience, just looking to clarify what is being discussed.
I realize that a short barrel makes the effective range significantly less than even a 16" due to the velocity dependency of the 5.56. I am looking for a compact, effective platform out to 200/300yards max without adding another caliber.

 

[RTH1800]

Longer being my standard 18" and my past use of 16".
I used both the MK 262 load of 77 SMK as well as 52 grain Hornady and 60 grain Sierra's. When I saw the poor proformance of the 77 gr SMK I thought the lighter bullet might be faster and have more energy. It did not do as well. The 77 is still the best but not good enough.
I found it poor at all ranges tried. 25 yards to 300 yards with all bullets.
I get excellent results with the MK 12 18" Douglass barrels to 500 meters and beyond with MK 262 ammo.

I am not anti SBR and have really worked to find one that will do the jobs I want. This with at least 6 uppers, thousands of rounds and 10 years of experimenting off and on. I do keep one nearby in my house for HD as I am sure it will be more effective than a .45 ACP.

I also tried the LAW folder but it added much weight that I found distraction. It was about a pound IIRC. I wanted light, compact and good kills, asking too much I suspect. I only got compact. Hope you can do better and share what you learn.

 

[RyanScott]

Ifnit was legal for hunting I’d make a 12” 224V and shoot Hornady 75s for improved terminal effect.

 

[Shrubjr]

My experience pales next to some of these guys, but I've tried 16", 14.5", 11.5" and 10.5" all in 5.56.

11.5" is as short as I would ever go in 5.56.

I have a 14.5 Battle Arms Development barrel, and it is my fav of all of them I've tried. The smoothness gained by the mid-length gas system is very nice, and noticable to me!

I would like to try a 9-10.5 300BLK someday though.

 

[TanktheFrank]

Yep... I'm gonna sbr it

 

[buggsb]

I have run 10.5 and 11.5 barrels in 5.56 for years without issues. In order to make an informed decision you need to understand the "mission" for that AR. Obviously the shorter barrels give up significant velocity and begin to sacrifice effectiveness at some point. However when clearing structures where engagement distances are likely well under 5 yards it really isn't a concern. With that said I was consistently banging steel last week out past 400 with my 10.5