Best subsonic 300blk load for semi auto rifle?

[ThePastafarian]

I am about to finish building my 300blk AR pistol. I was wondering if anybody had any known subsonic loads that will function in an AR platform

 

[ATLRoach]

What bullet are you trying to use? I can give you my recipes but they are for a 16" carbine. I load for 200gr SMKs, 208gr AMAX, 220gr SMKs, and 240gr SMKs. I'm about to purchase some 203gr Palmettos and give them a go too.

 

[lostgeorge75]

Gemtech 187gr has functioned perfectly in my 8.5" blackout.

 

[Lumberman]

Has anybody shot a 208 AMAX sub load at a deer yet? I tested a round a couple of nights ago by firing it into a road kill possum on the half shell with a couple of gallons of water and a compressed bale of peat moss behind it. Bullet went thru all four and I could not find it. Did not blow a big hole out of the dillo. I am not sure that the bullet is mushrooming at sub speed. Sat in the woods with it this morning and was only going to take a double or high shoulder shot if I had one.

 

[kscoggins]

208 amax will not expand at all at subsonic. Your only hope is the bullet tumbling or spinal cord/brain shot. Outlaw state and Lehigh defense makes bullets that are purpose built for hunting at subsonic velocities.

 

[sold7]

yep it should tumble not expand designed for clearing rooms not deer