Need Input On My New 300 "whatever" Rifle
 

Ok this thing has got me baffled. It sounds loud as hell to me and I would like some input on what you peeps think.

Here is the gun:
10" 300 blackout barrel
Pistol gas with Paladin Machine Block
FailZero BCG, Ranier Upper
Can is a Liberty Black Raven II

I am running 11.5 grains of AA1680 with 220 SMK at 1050fps. Gun runs great with ejecting and BHO working on last round.

The thing sounds loud as hell to me even when I am standing away from it. I have never heard another 300 "whatever" so I have no basis. I guess I am comparing it to my Sub 308 bolt gun and the same can. There is a hell of a pop on the semi auto and does not feel hearing safe to me. Also if I shut the gas totally off it seems even louder...wtf?

Anyway if you have any input let me know. The YT Channel below has the vids of the 300 "whatever" and my 308 bolt gun with Subs and Supers. Same shitty Droid video camera about 10 foot away.

http://www.youtube.com/user/Code9mm?feature=mhum

videos are hard to tell over the net sometimes ..

I'll bet you are getting action noise along with your loads being "on the edge" of going supersonic.

I have no experiance with that powder as I try to use H110 whenever possible .. its what works for me.

my honest suggestion would be to try different powders and different powder charges.

sorry I cant offer more help.

I hear you on videos not being great. I am using a chrony so I know where the loads are shooting. They are staying well below subsonic.
I have already tried 2 other powders. H110 and 4227. Neither will cycle the rifle in the subsonic range. They all have they same sound when fired. It is really a shot pop sound and not out in front with a super crack.

just brainstorming ..

what velocities are you getting through the chrono?
what powder charges have you tried?
have you tried a different suppressor? I know Liberty makes good stuff just thinking out loud.

something is not right .. hopefully with enough info we can (as a forum) get you headed in the right direction.

I am in the 1020 to 1040 range. I started at 12.5 and worked down to that load. My 9mm can would work, but it's threaded 1/2x28 so I need an adapter. I know the Liberty can is pellet gun quiet with my 18" .308 sending 160FTX's with Trailboss.

Try reducing your charge. A few tenths less will not change the velocity much and if you run them around a 1000 fps it will quieten down some 1680 seemed louder in my ar also. I am using N110 and AA9 now.

lighter charge,faster powder :smile: unless your gas port is in the carbine position....

I am in the pistol port. If I can not get H110 or A4227 to cycle what would you recommend? I was thinking N110 as my next step...unless anyone has other thoughts.

N110 is really good, Enforcer,#9, I've also used Power Pistol, and SR-4756 (not9) in 10.5" barrels with pretty good result... H-110 not so much good result.

Make sure your gas block & tube are tight. You may be leaking a little bit of gas out of there that creates a louder impulse sound.

Note that the shorter barrel is going to be louder than your 18" barrel, and the action noise of the AR will contribute somewhat to what you are hearing. My .300 WTF is nowhere near as quiet as my suppressor is on a .308 bolt action with a long barrel and subloads, but it can put a lot more rounds down range and is much lighter and easier to carry.

As others have stated, powder will affect the sound and the faster the burn rate, the less your suppressor will have to minimize since the idea is to have the powder fully burned before the bullet reaches the suppressor. Alliant 2400 and N110 are what I use for my pet loads. I wasn't happy with the accuracy of AA1680.

If you can Chrony your loads, you will take a lot of the guesswork out of your rig if it is just on the transonic cusp.

How do you like the Fail Zero?