I have an older Savage110 chambered in 7mag. It's will not fire and only dents the primers. Now and again it will fire. Inspected firing pen and it is clean with no oil, l bolt appears to be in order. I'm thinking the firing pen must be worn down as it doesn't appear broken. Is there a measurement or a way to check and see if it is within spec? I know the firing pen needs. 050" protrusion to ignite a case but I don't know how to check it.... Any other ideas that will help fix this problem would be appreciated.