[steve4102]

I just got my EAA Witness Elite Match 10MM back from Customer Service. I had to send it in cuz it was puttin some serious bulges in the ejected brass along with some primer wipe.
They said they installed and fit a new upper half. I took it out for a test drive today and the bulging brass is all gone.
I do however, still have some very significant wiping of the primers. Is this anything to be concerned about?

I tested several powders with loads from start to max and all showed primer wipe.

I installed a 20lb recoil spring before I went to the range. Do you think the heavier spring may be the problem. Or maybe not heavy enough, I have a 22lb spring I could try as well.

Thanks
Steve

[calaverasslim]

What is primer wipe?

[SDC]

If the OP is thinking of what I think of as "primer wipe", this is where a ring around the firing-pin impact bulges out far enough to get squished or sheared off flat by the breech-face as the pistol goes through its unlocking process, leaving an area that looks like a razor was used to slice off part of the primer (though not usually completely through the primer, which would be bad). If it happens even with factory loads, I'd say it's just something you'd have to live with, but if it's happening only with your 10mm reloads, then there factors in your handloads that you can change to deal with it. Some designs are known to have larger-than-normal firing pin holes in their breechfaces, and this can cause the described effect even with factory ammo.

[The Lone Haranguer]

"Primer wipe" is a teardrop-shaped firing pin impression, accompanied by a drag mark (scratch or gouge) following the "point" of the teardrop and leading away from the primer, sometimes into the brass. This is because the firing pin does not fully retract after the round has fired and the slide is traveling back during ejection, causing the case to drag across the firing pin as it is thrown clear. It is not in any way harmful, except sometimes to the case if the primer pocket edge is gouged. Kahr will tell you it is a normal condition for their pistols, even saying so in the owner's manual.

[Joe Demko]

Some folks will tell you that primer wipe is a sign of premature unlocking. Others will say it is not.
I owned a S&W 4566 for many years that was unnaturally accurate. It would shoot right alongside any Gold Cup. It also exhibited some primer wipe; the firing pin strikes were ovoid in shape, but no gouging.
I didn't make any effort to correct it; I didn't want to upset whatever equilibrium made the gun shoot so well. I shot the hell out of that gun for years and sold it to a friend who is still shooting the hell out of it. It is still accurate and still shows some primer wipe.
My advice is not to get too worked up about it.

[Drail]

A little bit of primer wipe is not a problem. If it becomes bad enough the tip of the pin can get sheared off. Most pistols exhibit some wipe.