Barrel lengths

[rob_s]

What is going to be available from AAC?

What is the "optimal" length where improvement in performance (velocity?) starts to drop off? Typically we see that as we add 1" at a time we get substantial improvement up until a point where the improvement is incremental. The last length or two before the drop off are usually seen as the optimal length. This is true of 9mm, 5.56, and 6.8 (the three I'm most familiar with).

[Stickman]

I know that 9" and 16" have already been commented on. I'm not sure what else is floating around.

I've also heard a few people commenting that the barrel should have been 10.5" instead of 9". I would point out that while 10.5" barrels might mean something through a 5.56, its apples and oranges when we are talking about 7.72x35.

[eazenutz33]

I know that 9" and 16" have already been commented on. I'm not sure what else is floating around.

I've also heard a few people commenting that the barrel should have been 10.5" instead of 9". I would point out that while 10.5" barrels might mean something through a 5.56, its apples and oranges when we are talking about 7.72x35.

maybe difference would be seen with rail choices???

just speculation on a good reason for me to want a slightly longer barrel when there would be no appreciable gain in ballistic performance. I know I like to use an AFG...on a shorter rail its not quite as comfortable without extending the stock further which makes the gun longer in comparison to your body then having the stock in and AFG further out on the rail. At the same time, using a 9" rail with a 9" barrel and AFG is possible on the furthest forward position on the rail....but I would think it could make it nice and warm with the silencer that close.

For me personally, I like a midlength rail....not longer....not shorter, and the same goes for anything like Magpuls plastic handguards. As long as the silencer wouldnt get too hot running sub/super sonic ammo when using a midlength rail and 9" barrel (fit inside the rail?)...I would find this ideal for ME. If not, maybe a 10" or 10.5" with nothing else changed might be more in order for someone like me....as long as it still ran correctly.

[rob_s]

I agree that going with non-standard barrels will mean having to re-calculate handguard needs. a 9.0" barrel kind of leaves you in an in-between spot with existing rails.

[-k-]

Maybe I can make good money with the old M4 RAS 8" handguard that is in my spare parts bin...

There are several companies making the 300 Fireball in different lengths, I expect them to change over to the SAAMI version so there should be options available.

[300Blk]

10.5 first existed in the 5.56mm world because it is the shortest length that works with the USGI front sight/gas block. When you change over to a low-profile / short gas block, I would rather have an 8 or 9 inch barrel with a 7 inch rail. Not in 5.56mm of course - as 5.56mm needs longer barrel lengths. In any case, I find 300 BLK interesting in 7, 8, 9, 10, 10.5, 12.5, 16, 18, and 20 inch barrels.

[silentbushmaster]

How does the 300 Blackout in a 12.5 length barrel perform VS the 6.8 SPC in the same?

[300Blk]

I predict it will be a toss up but the 300 BLK will have far less muzzle blast, lower ammo prices, and subsonic capability.

[silentbushmaster]

Since suppressors are being used, I don't see muzzle blast being an issue. Since ammo prices have yet to be posted, that at this point is a non issue. It does have the reliability of sub sonic use, while the 6.8 SPC can and has sub sonic loads. The 6.8 SPC does have brass available. While the 300Blackout may have a very slim advantage in a very short barrel, it does start to loose ground with longer barrels. Don't get me wrong, the 300 Blackout has a place, I would use it more for sub sonic use.

[eazenutz33]

Since suppressors are being used, I don't see muzzle blast being an issue. Since ammo prices have yet to be posted, that at this point is a non issue. It does have the reliability of sub sonic use, while the 6.8 SPC can and has sub sonic loads. The 6.8 SPC does have brass available. While the 300Blackout may have a very slim advantage in a very short barrel, it does start to loose ground with longer barrels. Don't get me wrong, the 300 Blackout has a place, I would use it more for sub sonic use.

fair statement.......I would be using it for under 300 yards max, and the thump of using it subsonic for close up shots is a BIG draw.

I think this would make alot of sense for military.....use the same bullets for long range 7.62x51 and use it for CQB/battle rifles in 300 BLK, just different cases and magazines.