13.7 Pin Weld

[7mmShooter]

Hey guys, pondering a 13.7 Pin and Weld barrel setup... Anyone have one they've chronographed velocities with? Can't find much on the actual velocities people are getting with them, but if I had to guess somewhere between 25-2600fps with 77gr would be doable. Anyone done one and gone back to 16" guns or have you stuck with a 13.7 between the two length choices?

Thanks in advance!

 

[PBWalsh]

I personally went with a 16" after deciding on both options. My main reason was to be able to reuse the muzzle device. Its a great idea though if that doesn't apply to you, short is right for most realistic uses. I think it just depends on your purpose and whether you will actually benefit from either barrel.

 

[7mmShooter]

Yeah, I keep tossing it up for that main reason you mentioned. Considering the ranges I have available to shoot currently (300 and under), I think a 13.7 with a Nox would suit me just fine. Last time I ran the numbers vs my current 16" setup, 13.7 with a Nox would save me about 10.5 ounces and like 1.75" in length.

 

[Kadams1563]

Just about everything a 16” gun will do a 11.5” gun will do. Go short as possible. I vote 13.7 and that’s what I’ll go with when the 14.5 gets rebarreled.

 

[PBWalsh]

Yeah, I keep tossing it up for that main reason you mentioned. Considering the ranges I have available to shoot currently (300 and under), I think a 13.7 with a Nox would suit me just fine. Last time I ran the numbers vs my current 16" setup, 13.7 with a Nox would save me about 10.5 ounces and like 1.75" in length.

That is a ton of weight, what contour is your 16"? Could go with something like a BCM ELWF if weight is the only concern. That is a 21.5 oz 16" barrel. Their 14.5" is right around 20 oz I think.

 

[7mmShooter]

That was comparing the Rosco 13.7 Purebred with a Nox and the 12" M4E1 rail to the 16" Rosco Purebred (with the 15" M4E1 rail and JP Tank brake I'm currently using on my upper). But the numbers may be a bit off considering I've never gotten a clear cut answer on how much the Nox weighs (I've seen anywhere from 2 ounces to almost 4 ounces, but I'd bet it's closer to 2). The weight is no big deal, just a bit surprised that there was that much of a difference.

 

[loveha]

I want the ability to pull the muzzle device to clean the crown if I want/need.

 

[WirgmanUSMC]

If you’re only shooting 300yds then I would do the 13.7 for sure. I’ve shot my 10.3” out to 725 with good success, and everything inside of 500 was a cake walk. I don’t even own any ARs over 10.5” anymore.

 

[thehun]

I went with a 13.8" in my LMT MWS last year and it was awesome!!!

 

[7mmShooter]

I've heard it's only like 40fps loss in velocity over a 14.5, so should still run some pretty good numbers

 

[MPDS13]

I agree with guys above. Go as short as you can. 13.7” will do everything the 16” will do. Especially at those ranges.

 

[rlsmith1]

Why would you do a 13.7" pinned to 16" when you can do a 14.5" and pin to the same length? Weight is negligible, dwell time is increased, velocity is slightly increased and you can pin many more devices. I like to watch weight too, but the design of a handguard has more to do than the length when it comes to weight (with the lightweight ones anyway). I have KMRs on my rifles and the 14.5" with a 13" handguard isn't noticeably heavier than the 12.5" with a 10" handguard (the 13" weights a whole 1.6 oz more). I've got longer arms so I actually prefer the longer handgards.

The only good argument that I've heard for the 13.7's is they bring the weight of the suppressor back which can definitely make a difference. Otherwise, 16" is 16" and I'd rather have more barrel than muzzle device. Dwell time is increased and when running suppressed, muzzle pressure is decreased which is better for suppression.

If you're set on a Dead Air mount, their new single point break should get a 14.5" to 16" with a few shims.


BTW - my favorite 556 is the 12.5" as it gives a great balance of speed and maneuverability. Suppressed with a Sandman S, it's about the same length as a 17" barrel with muzzle device.

 

[7mmShooter]

14.5 crossed my mind as well, definitely offers a lot more options for muzzle devices.

 

[1911hombre]

14.5 crossed my mind as well, definitely offers a lot more options for muzzle devices.

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