BCM .300blk upper with omega - what barrel length?

[Airwolf]

I am ready to buy a sbr 300 blk upper. I tend to like BCM and plan on getting either a 9 inch, 12.5 inch upper they offer. I will be running an omega suppressor, as that is my only .30 cal can.

I have drove myself crazy doing research on barrel length and its impact on quietness. The overall consensus is that shorter barrels are always louder. Some say they can tell little difference between a 9 or 10 inch barrel vs a 16 inch barrel in 300blk..... then some will say they can tell a noticeable difference between barrels of only a few inches difference.

I have very damaged ears with severe tinnitus and sound sensitivity and will no longer shoot 5.56. I will only be shooting subsonic 300blk with a suppressor and will be wearing ear plugs and ear muffs (my ears are that bad).

Does anyone have any experience between any difference in loudness with only a few inches of barrel length difference. I always thought that since the 300 is far less pressure than 5.56, barrel length would not be as critical, but sound suppression is my primary concern without having to go as cumbersome as a 16 inch barrel. Is 12.5 inch barrel likely my sweet spot?

[quiettime]

9" will be a lot handier with can on. I shoot subs so extra length doesn't benefit me anyway but you don't lose much velocity

[CanOfWhooppass]

Your gains for going over 9" is just about non existant and as said, less handy.
Unless your try to extend the range to its max limit with supersonic ammo and a scope, go 9.

[John A.]

I'm using an 8.5" barrel.

With that said, if I could go back and do it over again, I'd go 10.5 or 11".

The powder that I'm using burns out pretty quickly. If I had a couple more inches of space before the suppressor, I have no doubt that it would be more quiet.

You won't really gain any velocity between the two. But from a suppression viewpoint, get the longer option.

[cdl]

Of IMR 4227, I use 9.3 gr in a 10.5", 9.5 gr in a 8.5" and 10.0 gr in a 5.5", all to get around 1000 fps.

9.3 gr is quieter than 10.0 gr in all of them... but 9.5 gr in the 5.5" at 955 fps is plenty quiet and works very well.

I like a shorter barrel mostly because that's what the S stands for in SBR.

(By my calcs, a 300 Blk sub in a 5.5" is about 2/3'rds the muzzle pressure of a 16" 308 and I'm sure the Omega isn't smart enough to know the cartridge length.)

[blackops_1]

I've shot 300 blackout supersonic in 8.5 to now 16 inch barrels. 16 is the best
for keeping the volume lowest. I have the same hearing issue now because of the
8.5 inch as a matter of a fact. Was shooting with a can, ear plugs and muffs. Testing some hot reloads of mine, about
100 of them under a covered outside shooting position. Didn't notice that my ear plugs
had worked loose due to the muffs and can. No pain and didn't seem louder over the course
of fire. So now the Eeeeee is only noticeable at night when trying to sleep, gotta use a fan.

[Deansstern]

I’m using an Omega45k direct threaded into my 16 inch Faxon Arak 300. After hearing this I’ll definitely start putting on ears for it. Been reloading 150s just under 2000 FPS lately. Can just barely get them seated with all the 1680 powder in there!