AR-15 Barrel Length

lpbarker

New member
Rating - 0%
0   0   0
Location
Saskatoon
Im looking to get an SBR AR-15 and I would like input to what length of barrel I should get?
I like 10.5 but would a 12.5 be better because it would have less muzzle blast/concussion and better ballistics?
 
With regard to blast and concussion, the brake or flash hider you put on will make more difference than a few inches either way. Ballistically, well... it's a paper puncher regardless.
 
The shorter you go, the harder it gets on extraction because of the lower dwell time, causing early extraction when there is more pressure left inside of the case that's expanded in your chamber. 10.5" barrels are fun and I always recommend a little rubber O-ring around the spring of your extractor to make the extraction more reliable, at the very least. Some bolts already come with it.
 
...
I like 10.5 but would a 12.5 be better because it would have less muzzle blast/concussion and better ballistics?

The very short answer is "yes" on both counts, but the above responses are also valid.

Personally, I HATE muzzle blast, so would be more inclined to go with the longer barrel even with the best of brakes (especially if shooting indoors). Regardless of the barrel length you choose, the right type of brake will have a much greater effect on blast felt by the shooter.

Ballistics are definitely affected, but whether it matters to you or not really depends on your intents and expectations. If you're not sure whether or not it matters to you, then it probably doesn't.
 
go with a linear comp on a 10.5. lots of fun. any brake on a 10.5 that directs gas sideways will feel like a punch in the face every time you pull the trigger.
 
All these SBRs are (to me) annoyingly loud (the substantial increase in muzzle blast makes them so) and have a carbine length gas system which is known to be the least reliable.
 
For what it's worth, I've run a 10.3 SBR with a DD MK18 barrel, AAC flash hider paired with an H buffer for a few years now and don't find anything to be excessive in terms of "concussive force" or muzzle blast unless I'm shooting from barricades, but that's kind of a given.
While on paper, you may say they're the least reliable but in the real world they shoot just fine as long as you set them up properly. I've never once had extraction issues, or any malfunctions of any kind with that set up.
Yes, their is a mild increase in muzzle rise but proper shooting techniques will mitigate that.
Is my 16" mid length rifle with a Surefire warcomp on it "softer shooting"? Yes, but only marginally.


The big difference comes between those who are serious shooters, and bubba who says #### like "y'all wanna see a big ####in fireball?!" through a wad of dip in his mouth.
 
My personal favorite is a 12 inch barrel, I've owned a 6.5", 10", a few 12", a 14.5", 16" (still own), 20" and a 24" 308 and all of them are fun but anything shorter than a 12 inch is in my opinion a waste of time. With a 12 inch you can put a nice free floated forend on that lets you get a good hold on the rifle without worrying about over reaching and shooting yourself in the hand, you can actually run a brake on it even though I prefer a 14.5 or longer if I'm going to run a brake because of the concussion blast.
The 10" and shorter are fun for a little while then I find the novelty wears off and all you're left with is a punch in the sinuses every time you pull the trigger unless you run a linear comp.
Depending what you want to do with the rifle the optimum barrel length changes. I built my 16 inch for 3-gun but if I was going to do more CQB I like the 12 inch. If you want to go short and don't care about shooting past 200 yards maybe a 9mm AR would be better for you.

The real beauty of the AR platform is that you're not stuck with anything. If you buy a 7.5 inch barrel and shoot it for a couple months and decide you don't like it just sell the barrel and the handguard and buy a 12 inch with a nice handguard to go with it. If after a month or two you decide you want something different just buy something else or build a second upper to swap over whenever you feel like it. The options are endless and you can change it any time you want.
 
My personal favorite is a 12 inch barrel, I've owned a 6.5", 10", a few 12", a 14.5", 16" (still own), 20" and a 24" 308 and all of them are fun but anything shorter than a 12 inch is in my opinion a waste of time. With a 12 inch you can put a nice free floated forend on that lets you get a good hold on the rifle without worrying about over reaching and shooting yourself in the hand, you can actually run a brake on it even though I prefer a 14.5 or longer if I'm going to run a brake because of the concussion blast.

The 10" and shorter are fun for a little while then I find the novelty wears off and all you're left with is a punch in the sinuses every time you pull the trigger unless you run a linear comp.

I sort of agree with some of that... but my experience has been that a short barrel rifle, with really any flashhider or even any of the brakes I've used, does not create a blast issue at all for the shooter himself. The issue is more for the guys on either side, if you use a brake, but really only with a brake. I run 10-11.5" uppers on a few guns with C9 or AAC Blackout flashhiders, have not noticed the 'punch in the sinuses' issue while using any of them, and have never had complaints from other guys shooting right beside me behind cover in dynamic shooting situations. On the other hand I've been shooting from behind barricades beside guys (actually one guy in particular!) who runs a brake on his gun, and holy #### that was unpleasant!

I personally don't run brakes on short guns anymore (except my Stag, which is a recent addition) not because of any issues I experience shooting them, which were nonexistent, but because if I have guys shooting right beside me, I don't want to have them struggling to focus with that blast from my gun right beside their face! When I was just doing run-and-gun competition, where it's just me, brakes were great for sticking to the target, but now I prefer flashhiders for their utility in reducing my signature and allowing the guy beside me to do his thing.

Overall short barrels are not a problem or at all unpleasant to shoot, in my opinion. You just need to choose your muzzle device depending on what kind of shooting you're doing.
 
Last edited:
Well, I guess I'll ask the question, since no one else seems to have done so. What is your intended purpose?

If you plan is to dress the thing up like a barbie doll and pose with it for photo's for the web, then shorter looks cooler. If you are actually planning of shooting the thing at any distance in any sort of real rifle type matches out to 200,300 and 500m then longer is better, for iron sights a good old 20" tube will work just fine, for 3 gun or IPSIC type stuff 14.5" seems to work best.

Purpose will decide your barrel length. And those obnoxious muzzle devises, we will shun you to the far reaches of the range during a match. LOL

Scott
 
Well, I guess I'll ask the question, since no one else seems to have done so. What is your intended purpose?

If you plan is to dress the thing up like a barbie doll and pose with it for photo's for the web, then shorter looks cooler. If you are actually planning of shooting the thing at any distance in any sort of real rifle type matches out to 200,300 and 500m then longer is better, for iron sights a good old 20" tube will work just fine, for 3 gun or IPSIC type stuff 14.5" seems to work best.

Purpose will decide your barrel length. And those obnoxious muzzle devises, we will shun you to the far reaches of the range during a match. LOL

Scott

Lol, yes.
I have a JP competition brake on my 16 inch and I was not popular on the line at the CQB course I did a couple summers ago. Lucky for me I ran my 12 inch PWS for the first day and a half which just had a flash hider and only switched to the 16 inch to see how it did since I built it for 3-gun.
Purpose should be considered long before cosmetics, looking tacticool only goes so far :)
 
You can always run a brake with a blast can on a shortie - that will push the concussion down range. As for carbine length gas systems being the least reliable -WTF? You mean pistol length is more reliable??
 
Back
Top Bottom