Anyone experience this???

[KCherry]

7wsm, Fed & Win brass, Fed 210 primer. H4831SC. Loads starting at 52.5gr to 58.7 gr. Sierra 175 gr GK. Shot from Win. 1885 Highwall. Not really hot, but primer mark on all of them is pushed back out and flat. This is happening regularly with this rifle. From hot factory to soft hand loads. At this time I am not really concerned as there are no other signs of high pressure. I sure would like to know if I am missing something here.

 

[Rem700addict]

It looks like to me your primers may not be seating far enough down in the pocket. When you prime one of your loads stand it up on a flat surface and see if it wobbles any, this can tell you if it is seating the primer flush with the face.

 

[KCherry]

The primers are set below the surface of the base. This has also happened with Federal and Winchester factory ammunition. I have wondered if the hammer bounces back enough after firing, the pressure pushes back and flattens out the firing pin indent.

 

[Barrelnut]

I'm kind of thinking too much headspace. I believe the primer does come somewhat out of the primer pocket from the primers own initial pressure as the primer fires. Then the powder ignites and the cartridge stretches which actually moves the primer back deeper into the pocket. If you have excess headspace the last part of the sequence may not be happening correctly.

 

[LoneTraveler]

I have not dealt with a Winchester High Wall action. But I had a similar problem. I inherited my dads Remington Model 722. Dating back to about 1952. At the range it popped the whole firing pin indent out of a couple cases, Gas came into the bolt, all the shells had a sharp burr around the edge of the firing pin indent. It shot about 2 1/2" groups. Checked the firing pin spring pressure and it did not equal its share of the 52,000 chamber pressure developed in the gun, Cal. 222 Rem. When I calculated it out. Had the Firing Pin Spring replaced by a gunsmith friend. No more firing pin holes in primers, no sharp burrs and it went back to shooting 1/2-3/4 inch groups like I remembered. Some way the firing pin is not supporting the primer when the gun fires. This is allowing the primer to flow back into the firing pin space. Does This Winchester action have a rebounding firing pin??? Or does the hammer lay solid against the firing pin, Till manually raised to half cock?? If it is in contact with the hammer, It could be the Main Spring is Just Old and Weak. BE SURE TO WEAR GOOD SAFETY GLASS and be careful till you get this problem resolved. Good Luck.