AR-15 sub sonic load help needed

[bob6117]

I am trying to devolop a sub sonic load for my AR.
I shot 5 groups today @ 100yd., all grouped around 2" but hit the target completely sideways.
There were no baffle strikes at all.
My loads were:

Lake City 5.56 brass
5.2- 6.0 grains of Trailboss in .2 grain increments
Wolf .223 primers
Hornady .224 75 grain bthp
COAL 2.250

My rifle is a 16" barreled gas piston POF, I tried on the suppressed setting on the gas block and the normal setting.
The rifle would not cycle either.
I did some research in the sub sonic load thread before loading and know guys are getting good results between 5-6 gr. trailboss.
Any help would be appreciated.
Thanks
Bob

 

[tsavo303]

its not going to cycle on any setting
i would just buy a 300blk if that is a requirement. or .22 upper with 60gr aquilas

what is you goal/purpose?

 

[country888]

I made up some last year to play with. I use 4.6 gn of Trail Boss with 55gn SP in a 7.5" barrel. They wont cycle but are very quiet and fun to plink with. Have you shot them through a chrony to check velocity? What is the barrel twist?

 

[Killswitch Engage]

I use 3.5gr tb in my 223 sub loads with 55 gr xm193 pulls. Shoots under 1moa and is quiet as hell. Obviously will never cycle the gun. Your gun sounds like it has too slow of a twist to stabilize the heavy 223 bullets.

 

[jwp6114]

Wow... It's just a matter of time until you have a baffle strike and jack your can up...

I don't understand why people even try this. If your trying to be quiet, chamfering each round will be loud.

Better off slapping in a 22 conversion and shooting .22 Cci sub sonics

 

[sic65stang]

Jwp is right. I cant believe you shot a load through your can without ensuring first that it was not tumbling.

You are not going to get that rifle to cycle with a sub. I agree it is cool to have a sub load for an ar, but if I have to cycle the round I might as well have a bolt action...

 

[bob6117]

Thanks for all the reply's , my twist is a 1/8 and I use 77gr. smk over 23.7 of Varget for my standard load.
The sub sonic load is hitting nose first at 50yd., but sideways @ 100yd.
I dont have a specific need for a sub sonic round, I'm just messing around with some leftover Trailboss and Hornady 75gr. bthp.
Thanks again
Bob

 

[xdeano]

You definitely should be using a chrony when working up a sub load. Start a little high and work your way down to avoid getting a bullet stuck. Also work the load without the suppressor on. When you get the load in that 1050 range and you know youre not key holeing then stick your suppressor on. No sense in destroying an expensive item just playing around.

I agree with a previous poster, just pick up a 300blk upper and have some fun.

Xdeano

 

[jwp6114]

Bullet stability is a factor of bullet length and rpm upon muzzle exit...

Your 8 twist would be fine at SAMMI velocities, but not putting enough spin on the bullet at 1050fps... Hence the instability.