Berry's 200gr Keyholing

[Leadthrower74]

Hello all. New to the forum and 300 blk.

I recently started loading for my 8.5" 1:7 pistol. So far for factory rounds I have run 147gr S&B supers and 200gr S&B subs with no issues. I loaded up 10 ea of Berry's 200gr plated over 11gr-12.5gr of CFE BLK. All loads were unstable. The worst were the 12.5gr through my suppressor. These were shot at 25 yards since my primary goal was velocity and grouping to then fine tune from there. I did not expect all to be unstable. I have never had this problem before in my more than 2 decades of reloading. The range was from 850-1100. Any insight is appreciated. I'm rather perplexed.

ETA: The reason there are only 2 shots on the 11.5gr u/s target is because they weren't chambering properly. I noticed an oal variance in the bullets and suspect that caused chambering issues as the ogive was into the lands. I had a COAL range of 2.1895-2.193 and suspect those slightly longer ones were to blame. I plan to go down to 2.186 to allow me a "reliability" buffer.
http://imgur.com/gallery/6VQgq1z

[rebel]

You tested with a suppressor screwed on? Did you have a baffle strike?

[Leadthrower74]

First four loads/groups were without. Last 4 with. No baffle strike. I did not know they were unstable until all groups were shot and I went downrange. I have only ever experience keyholing once before and that was out of a crappy Jennings pistol. So I never even considered it, or considered checking.

[JeffroJ]

Are you crimping at all?

On Berry's site:
"We recommend a light crimp on the bullet, just enough to put pressure against the bullet without denting or deforming the plating. If you were to pull the bullet out of a case with the proper crimp you would find no more than a scratch on the surface of the plating. If you are denting or deforming the bullet, your accuracy will suffer and the bullet may start to tumble before it hits the target."

[Leadthrower74]

Yes I am crimping using a Lee FCD. I loaded up some more testers in .2gr increments where I was getting the best grouping/stability. If these act up, I will try no crimp on the next ones and an even lighter crimp. I am not crimping much. But maybe I'll pull one to see. I will also compare to my 200gr S&B subsonics for stability.

[JeffroJ]

My berry's 220 grain loads looked like yours, slightly elongated holes at 25 yards, out of an 8" 1/7 barrel. I backed off the crimp until it was just removing the bell from my lyman M die, and leaving no crimp mark. I also bumped up velocity wondering if that was causing it, my loads were around 900 fps, now between 1k and 1050. Anyways, my holes are no longer elongated.