RF firing pin length

[oldred]

I need to know the approximate length the firing pin should extend out past the bolt face (or breech block in this case) for a 22 RF with the hammer all the way down, that's a 22 WMR if it matters. I have several 22s I can measure from but none from which I can do so at the moment so I would appreciate any advice on a starting point, maybe just a smidgeon long and I could cut it back while working with a fired case?

[John Taylor]

Rim thickness for a LR is .043", the mag may be a little more. About .030" should be more than enough. If it hits the barrel it will cause a ding on the end of the chamber which will make it hard to load and extract.