I have yet to do a pin modification, and have "yet" to have a slamfire. I'm not particularly proud, as a slamfire could very well be in my future.....
But, there are steps that can be taken to prevent a slamfire with the existing free-floating pin.
1. Inspect the bolt, and bolt face for damage to the body and "volcano" effect around the pin protrusion on the face. If all looks OK, then....
2. Take the pin out of the channel (punch out retainer), make sure it is straight and undamaged especially along the 'stop' ridges.
3. Clean the pin channel in the bolt with brakleen and a pipe cleaner until no more dirt/cosmo comes out.
4. Re-assemble and check that the pin "rattles" in the body when shaken. No rattle, then start over cleaning or check for proper assembly.
5. Pin protrusion should be no more than .070 inches. Normal is .063 +/- a few thousandths. If greater than .070 then the bolt face can be sleeved to reduce the diameter of the pin hole and bring protrusion back into specs.
6. Use only Berdan primed, mil-spec ammo. These were not designed for Boxer primed or SAAMI spec cartridres. If using SAAMI spec ammo, then a springed pin IS recommended.
7. Do not oil pin, as it allows for crud to build. Clean pin and channel regularly.
Following these precautions will greatly reduce the chances for a slamfire incident. YMMV.
