Check your base-pin latch screw to see if its backed off. If it loosens during shooting, it loses its grip. If this is O.K. Check the base pin latcth by removing it from the frame. It should be square shouldered, if its battered from recoil, it will allow the base pin to slip. Replacing this is a simple and in-expensive fix.

If all is well as far as battered parts, your base-pin may be undersized slightly. I grip the end where it enters the frame with a pair of pliers to throw up a burr at this point. This slight upset increases the diameter slightly for a more snug fit.

Bob Wright

Not uncommon at all.... esp if there's crud about.

I don't recomend the burr trick though. It causes 'risers' and can lead to stress failures. Not saying it will or has but....that's how metal works. I've known some that drill and tap the head for a set screw. But....

If your pin is ejecting, find out why.

I'd go with a Ruger factory replacement.
O/S basepins require fitting, line boring etc. Not the hot ticket for your force cone if she has a lot of miles on her. I'm also not a fan of fixing something that aint broke. They have to have clearance/wiggle room so the slug can center itself as it leaves the chamber, and, you can get the pin out for whatever reason.

Order a pin, the latch, spring and screw too. Replace it all as a complete set, just like a chain and sprockets on a dirt bike.