Help me choose a barrel length on next SBR

[L1A1Rocker]

Another 300blk. I'm going with either 8" or 7.5 on my next SBR and thought I'd ask you folks. Here's a pic with a delrin model of my QA/QD muzzle device. The barrel in the picture is 8".

Side view
http://i79.photobucket.com/albums/j154/L1A1Rocker/BLK%20sbr/HPIM1874.jpg (http://s79.photobucket.com/user/L1A1Rocker/media/BLK%20sbr/HPIM1874.jpg.html)

Top view
http://i79.photobucket.com/albums/j154/L1A1Rocker/BLK%20sbr/HPIM1875.jpg (http://s79.photobucket.com/user/L1A1Rocker/media/BLK%20sbr/HPIM1875.jpg.html)

What I'm thinking is if I go to 7.5 inches that should just tuck the shoulder of the muzzle device under the handguard and allow for clearance of the top port. I have plenty of clearance for the silencer to fit under the handguard so that's not an issue. What do ya'll think; go with 8 inches, or 7.5?

[cevulirn]

If you don't have to worry about can clearance, I'd go with the 7.5.

[Aggressive Perfector]

7.5 if your planning on concealing it at any time for any reason, who knows when that half inch less will allow you to tuck it away just a hair easier. Otherwise I'd just leave it at 8.

[Schuetzenman]

I always like the concept of having a pair of identical weapons, (though I have seldom achieved it). The only truly identical weapon system I have are Glock 19 pistols and in that case we have 3 of them. So I'd say build an exact duplicate of your current SBR in .300 blackout.

BTW have you Chronographed your 8" BO rifle? What speeds with what bullet weights?

[L1A1Rocker]

I always like the concept of having a pair of identical weapons, (though I have seldom achieved it). The only truly identical weapon system I have are Glock 19 pistols and in that case we have 3 of them. So I'd say build an exact duplicate of your current SBR in .300 blackout.

BTW have you Chronographed your 8" BO rifle? What speeds with what bullet weights?

So, you're saying I need to go 7.5 with both then? OK.


No I haven't done any chrono work on it. My 247gr cast were pushing around 1010 (IIRC) out of a 10 inch barrel.

[Schuetzenman]

So, you're saying I need to go 7.5 with both then? OK.


No I haven't done any chrono work on it. My 247gr cast were pushing around 1010 (IIRC) out of a 10 inch barrel.

Personally if it was me I'd stick with 10" to get more speed out of the round. Plus I think 10 to 11 makes a more balanced looking weapon. Reference my pistol build with a 10.5" barrel with a Sampson Evolution II rail FF handguard.
http://www.gunsnet.net/photopost/data/500/medium/Fun_4.JPG

[FunkyPertwee]

Delrin is a great material for valve components, but I've never heard of a delrin muzzle break before.

[L1A1Rocker]

Delrin is a great material for valve components, but I've never heard of a delrin muzzle break before.


Here's a pic with a delrin model

I have not turned out that actual muzzel device yet. I just recently received the cutting tool to cut the 5/8" ports. I think the model is now as complete as it's going to get. Also, the top port is WAY too big. I also have recently received the cutter holder to put a 1/8 in hole there. There will also be a 1/16 in hole in the right of the final brake to offset the muzzle's tendency to move right under recoil.

[nfa1934]

Check your suppressor warranty. AAC will warranty a can on a 300 BLK down to 7.5". YHM will warranty 300 BLK down to 8". Varies for other manufacturers. I wouldn't give up warranty coverage for .5" in barrel length.

[L1A1Rocker]

Check your suppressor warranty. AAC will warranty a can on a 300 BLK down to 7.5". YHM will warranty 300 BLK down to 8". Varies for other manufacturers. I wouldn't give up warranty coverage for .5" in barrel length.

Good advice, but my silencers are all home built on Form 1s.