I am not sure how a headspace issue could do what you describe. It sounds like an issue with muzzle blast and unburned powder, which would seem more like an ammo problem than a gun problem.
Are there any signs of bulged or blown cases, of barrel obstruction, or of powder residue in the magazine well and/or around the magazine?
Can you provide pictures of some of the fired cases and also of anything on the gun that looks odd or unusual?
Jim
I do remember the casings were black on one side: starting at the mouth running down about half the length of the case, but I assumed that the powder wasn't burning fast enough due the the shorter barrel of the P6. The mouth of the case was unusually flared, but nothing that made me worry.
I think Jim is spot on with it being a dirty ammo problem. If you can post up some pics of some fired casings that will help.
Have you tried more than one type of ammo? Is the problem specifc to one load or all?
Very possibly a weak or broken recoil spring causing the action open too early and spit back at ya. That could be ammo-related though too (hot loads).
Did you replace any springs on the pistol after you purchased it? Most of those P6s are around 30 years old and it's hard to tell how many rounds have been put through it.
I changed to a Wolf recoil spring and the and lighter Wolff main spring.
I remember using mostly 115, and 124 grains factory loads: American Eagle, Magtec, Blazer, Red Box Federal, and PMC. The only premium load I used was the Gold Dot, and it shot the best of all.
To both:
I was going to replace the barrel before I sold it. There was a nasty wavy ring on the middle section of the upper half of the barrel, and the muzzle was badly scratched and pitted.
Unfortunately I sold it some six months back, so I can not provide any type of pictures. The headspce thought came about randomly from my wild musings.
Actually my plan was to restore the entire gun, but I couldn't for various reasons. I wish I hadn't sold it now in some ways.
