Why is this EAA Witness doing this?

[REDLINE]

Friend of mine bought a brand new EAA Witness 10mm.  Don't know the specific model name but it is all steel and not a hunter or match model.  Generally seems to be a full-size platform.  Anyway, it is leaving a hash mark on the primers of all fired rounds besides the normal primer hit.  2 different loads have been run through the gun.  One was a weak factory load and the other a medium handload.  Anyone know why?

Also, what are the best aftermarket options to add or swap out/in for handling full-power loads from Underwood in this gun?

[Intercooler]

  It seems to be par for the course kind of. Just something that happens with the firing pin not being out of the way before ejection (I think). What spring is he running in it? The best approach is a 20-22lb Wolff spring and a Henning cone guide rod. That's about all that is needed to run up and down 10mm with them.

   He might also want to clean the firing pin channel and see if that helps temporarily.

[sqlbullet]

All mine do it.  They have a steel firing pin and a light firing pin spring.  Means the pin stays in place when slide heads back.  Inertia.

[blaster]

mine does it too. when I put the 22 lb recoil spring in it came with a heavier (?) firing pin spring which I also installed. it seemed to help but I still get some primer swipes.

[REDLINE]

What spring is he running in it?

Whatever came in it from the factory.

I'll clue him in on the other points you mentioned.

[DenStinett]

If you're still having issues with this....
Try looking here:
http://tz75man.forumco.com/
Sign-up and PM Rod Slinger
He's kind-of a Tanfoglio/EAA Witness Guru

[Intercooler]

The good news is the firing pin swipes don't hurt a thing on the pistol. I'm going to jinx myself here and say I have never purchased any replacement parts except sights and recoil springs. I have never overhauled the hammer spring, plunger spring, etc... ever 

[PCFlorida]

I know some of my Glocks have the identical look as well.

[REDLINE]

All great information and direction.  Thanks to all!

[Bruno747]

My rock island does this with hotter rounds, but not anywhere near the extend of the pictures in this thread.