Unsuppressed Muzzle Blast, SBR .223, .300, 7.62x39?

[broylz]

I am wanting to go with a SBR but will be a bit later before i can suppress it. i also think of its role as a PDW so the suppressor would also ruin the SBR for its short length to me, even though i will eventually suppress it.

that said, ive heard that a sbr .223 is pretty brutal for muzzle blast concussion and flame, and also heard similar about krinkovs in 7.62x39. is a .300 blackout any better since it is designed to have complete powder burn in 9" or so? i figure that subsonics should be similar to a pistol but thats just my thought process with no personal experience. i could be wrong.

how would you rate the muzzle blast of similar calibers, 7.5 AR15 in .223 like a noveske diplomat, a Krinkov in 7.62x39 - 8" barrel iirc, and a 8" Noveske or 9" aac both supersonic and subsonic?

[Mahk]

No experience with .300 AAC yet, but I have fired a couple Krinks and the blast wasn't abnormally bad, probably due to the muzzle device. I've had two 5.56 SBRs, one 10" and one 10.3" and honestly I don't think the muzzle blast is bad at all with a flash hider. Things will change a little if you throw a split chamber muzzle brake on it, but probably only for the people to your left and right unless you're shooting in low light. I've fired both weapons indoors and under covered ranges and I really don't think it's much worse than a 14.5" or 16" carbine. Muzzle device will make a huge difference.

[Tootsies]

Well I think it depends on what you run on the end. A flash hider sounds just like a 16" on my 10.5". But a comp will get your attention. Mine throws some flash but not always. Im sure with 8" you will get alot more. Once you adjust to the concussion of the break, its pretty nice, I love how flat mine shoots. With 300 im sure you will still have some bark but not as bad.
http://img32.imageshack.us/img32/7972/dscn07461280x814.jpg

[cabbynate]

To my surprise the muzzle blast is not to bad on my 10.5" 5.56. I run an AAC 51T Blackout and the blast is same as a 14.5" barrel to me. YMMV. When I run the 51T Breakout things tone up a bit. As Tootsies said once you are adjusted to the concussion of the break they aren't bad at all...