Primer cratering in a Panda

[82boy]

I put together a panda over the winter, and I having an interesting problem. The action is new and been sitting in a box since 1994. I find that my primers have craters or flow back when fire with an average load. (6PPC with 68 gr bullet and 29.2gr of n133.) I believe I am a bit short on firing pin travel, and that is causing my problem. I have measure the pin travel at .227 from cocked to fired. I am measuring my firing pin protrusion at .063 so If I subtract the pin protrusion from the travel I get .164 of actual travel. What should minimum travel be? How do I determin which trigger hanger I need? Thanks

 

[BoydAllen]

Two things:
Call Kelblys.
Weak firing pin spring?

 

[82boy]

The firing pin, is correct for the bolt head, the pin fits tight in the hole.
I did call Kelbly's and the Agreed that the firing pin travel is more than likely the culprit, There only answer they gave me was ship the entire rifle to them. Not something I want to do, if i don't have to. Especially if the answer is a quick fix, like changing a hanger, as they acted that was all they was going to do.
I have measured the firing pin travel well over a dozen times, and I keep getting the same numbers.

I seriously doubt that the firing pin spring took a set, one this stuff is made out of rocket wire which is not suppose to do that, and second, the gun never had a trigger in it is sat on the shelf, with the bolt de-cocked. Yes the spring was still under tension, but I seriously doubt that it was enough to take a set.