Gary, my 2 Lifters (10250 and 15728) have the stepped/crooked firing pins held in place with the threaded bushing. The guns had springs that were not real stout. They seemed to provide just enough tension to withdraw the firing pin after the hammer rebounded. The springs all had a little 'pad' on each end where someone used needle nosed pliers and made each end coil smaller than the rest of the spring. The large lifter plunger spring in both guns had the same little twisted pad, too.

Start a new topic and you should get some answers

Gary, I believe the post 50,000 serial number guns had the frames machined deeper to accept the springs.