Loud subsonic rounds

[LEO]

I'm looking for help and sugestions. I am shooting my 300 Blackouot using Hornady brass, 150 gr BTSP Hornady bullets, 12gr. of CFE223, which is supposed to give me a bit over 900fps. I fire several rounds, they seem pretty good, not as quiet as I'd like, but not too bad. Then occaisionaly, I get a very loud, supersonic sounding round go off. This might happen several times out of a set of 20 or so shots. I checked , no baffle strikes to widen the suppressor, rounds are crimped. Any help or ideas would be appreciated. Thanks

[ely]

im new to all this and not familar with the powder you are using, but just off the top of my head ,12grs seems a bit much for a 150 gr bullet, in subsonic, someone in the know will chime in shortly.
if you are close to the edge on subsonic the weather and humidity can push the rounds over the top. so i have read anyway. good luck and you will be happy when you get it dialed in.

[LEO]

Thank you. Did not consider atmospheric conditions, but I know that can affect sound travel. Good possibility. I was going to reduce the load, but wanted to have a starting point. Thanks

[Whole Bunches]

I just looked up that powder and its applications, as I wasn't familiar with it. See http://www.hodgdon.com/new_prod.html

Now, this is just MY opinion, but it appears to be WAY too slow of a powder for the 300 BLK...no wonder your velocities appear to vary widely. I would suggest a faster burning powder, say 1680, H110, Little Gun or even a faster powder if being used in a bolt action or single shot gun.

Edited to add: http://data.hodgdon.com/cartridge_load.asp The powder make doesn't list that powder for use in the 300 BLK.

[LEO]

I was thinking of trying Unique. I'd try lil gun, but powder is hard to come by right now. My choices are limited.

[Whole Bunches]

Shooting an AR, a bolt action, or a single shot? These loads certainly won't function an AR in other than a manual single shot mode.

I use a 150gr flat nose plated bullet with 5.7gr Unique for subsonic in my Handi Rifle with fine accuracy and 1041fps average. I use the same bullet with 5.8gr Unique in my Remington M700 for subsonic with great accuracy and 1081fps average. Be careful, with such a faster powder pressures can increase fast with not much of an increase in powder charge...I wouldn't go over 6.0gr Unique.

If you have any Winchester 231 powder, this load did OK in my Remington 700: 5.0gr Winchester 231, 147gr M80 bullets, 2.16" oal, 1056fps average.

[LEO]

I am shooting a Remington 700. I'll try Unique. Thanks

[MrM4]

Im still working on a load for mine, I bought some 1680 powder and and some 220gr Hornadays to try out. I was shooting CORBON factory subs threw my 10.5inch AR15 and a Lane LLC Scorpion Magnum silencer, they sounded great but it was close to $2 per shot.

[redfernsoljah]

I am only using 10.5 A1680 on a 208gr.

[LEO]

I changed to Win 296 powder and Sierra 220 gr, got much better results, but I'm trying to lower the velocity a bit more, right now I'm at 1050 fps. Still a bit louder than I'd like. Maybe I can't get much quieter.