My Sig P220 Elite Stainless with external extractor marked Exeter-NH has the solid milled stainless slide. My problem is the fppp continues to "walk" out of the slide. It is a single spiral style roll pin. From what I have read shouldn't it be a solid type? What are my options for replacement to keep it from sliding out? Would the two piece inner/outer style work? Thanks for your help.

Are you the original owner, or could the FPPP be a replacement? The solid pins are not a constant diameter and have a slightly larger splined head on the left side, so the slide has to be compatible.

No, I am not the original owner. It's possible it has been replaced before. I want to make sure I replace it with the proper pin. Could the roll pin be an acceptable replacement?

A properly sized roll pin should work because its only purpose is to retain the firing pin. Owners who have to replace the solid pin often use a roll pin because it is easier to install. The splined head solid pin usually requires great force to seat since it is a crush fit.

I'll order a new roll pin and give it a shot. Thanks for your reply. I appreciate it.