Very old Siler locks may have a worn tumbler or oversize hole in the plate. Sadly, a few suppliers sell Siler locks with "as-cast" unturned tumblers in oversize holes. These locks are no bargain.
Our Siler upgrade repair kit includes an anti-friction bronze bearing to bush a worn hole, and our newest tumbler, sear, and fly geometry, hardened and tempered for a smooth action and long service.
Tiny offset bearings minimize moving friction. These upgraded repair parts fit percussion or flint. This kit will fit flint or percussion, left hand, large Siler locks.