Anyone use this ammo yet? The 208 grain with the Hornady a-max projectile? I run 220 grain subs through my 300 blackout, no adjustable gas block, bootleg adjustable BCG with a 2.1oz buffer and runs flawless with ammo inc stealth. However I tried using these 208 grain, it short strokes, picks up the next round but won’t lock back when mag is empty, and the impact points are all over the place. Some are tumbling. Shouldn’t be under gassed with a lighter grain and I don’t think it’s building enough pressure to get the round up to velocity through the barrel hence why the round isn’t stabilizing. Just curious if anyone else has used them and experiencing the same issues.
What length gas system on your 16"? If not pistol, then you arnt getting enough gas to cycle the action. In my 16" with carbine length gas i only run supers for that very reason.
Pistol length gas is what I’m using.
Not really sure why the bullet would keyhole at just 50 yards!? The only thing I’ve heard of like this is “over-spin” on a thin-jacketed high-speed bullet (e.g., thin-jacketed 55-gr 5.56 in 1-7 twist barrel). Also, could the projectile be hitting something on the way past the muzzle?
Looking forward to hearing more 
I have pulled the suppressor multiple times checking for baffle strikes but don’t see anything. This is also shooting from a sled to dial new scope.
I had this in pistol config prior but wanted to gain a little range with the 16" barrel since it will be my primary coyote rifle until we get them out of the area on the property we hunt.
And these are 208g 1000 muzzle velocity 1/7 twist barrel. Don’t think overspin is even a possibility.
I’m baffled - no pun intended. All the big troubleshooters are probably getting ready for a quiet night, so tomorrow morning could bring new thoughts. Could be the ammo and PSA would definitely want to know about the issue.