How to determine a too large firing pin hole?
- Thread starter Hapworth
- Start date
Register to hide this ad
- Joined
- Apr 4, 2006
- Messages
- 19,389
- Reaction score
- 30,442
Happy Turkey Day Hap!
Usually you will notice peening around the hole and some sharp edges. A quick fix for some extended milage is to use a fine Arkansas stone with some oil and stone right across the face of the Bushing. Usually a minute with the stone will remove any sharp edges and make it flat again. It obviously won't close up the hole to Factory specs but it will get you a few more years before you should need to replace the Bushing. Protect and be careful of the recoil shield as to NOT mark that up too - you need a very small stone. After stoning, use the largest drill (by hand only) that will fit easily and just turn it with your fingers to remove any edge or debris that has gotten in the hole itself. This is just to clean out the hole and not to enlarge it.
If the bushing is too far gone the old one needs to be punched out and a new one pressed in. Last time I requested one from Smith they just threw one in an envelope and sent it out - gratis. Admittedly, that was about 6 years ago and it probably depends on who you get on the phone that day.
regards,
Chief38
Usually you will notice peening around the hole and some sharp edges. A quick fix for some extended milage is to use a fine Arkansas stone with some oil and stone right across the face of the Bushing. Usually a minute with the stone will remove any sharp edges and make it flat again. It obviously won't close up the hole to Factory specs but it will get you a few more years before you should need to replace the Bushing. Protect and be careful of the recoil shield as to NOT mark that up too - you need a very small stone. After stoning, use the largest drill (by hand only) that will fit easily and just turn it with your fingers to remove any edge or debris that has gotten in the hole itself. This is just to clean out the hole and not to enlarge it.
If the bushing is too far gone the old one needs to be punched out and a new one pressed in. Last time I requested one from Smith they just threw one in an envelope and sent it out - gratis. Admittedly, that was about 6 years ago and it probably depends on who you get on the phone that day.
regards,
Chief38
Last edited:
bushing damage
Cleaning this area is also critical. A dirty bushing that is impacted on the hammer side with shooting debris, dust and residue will certainly sustain added wear and tear.....and this dirt can contribute added wear to the hammer nose and or frame mounted f. pin as well. Dirt and debris here can also cause misfires and light primer strikes.
Take a look down inside the hammer frame cut at the back of the bushing (or pin) to check for dirt and debris. Use a good light and a magnifier. This area should be periodically and thoroughly cleaned with solvent and a brush, then flushed or blown out with compressed air. Cleaning the firing pin, channel and spring, on guns fitted with the frame mounted pins is also a good idea as this enclosed area can get dirty from regular use.
Also, make sure that the hammer nose or the frame mounted pin, depending on the model, is freely moving. These parts can get "gummy" from old lubricants and dirt.
If you have evidence of "peening" around the edge of the hole in the breech face on the older models fitted with hammer mounted noses, installing a spring loaded hammer nose will often eliminate or, at least mitigate this problem.
As to the OP's question, the bushing's obvious purpose is to support and protect the integrity of the primer. An otherwise properly fit bushing that has a visible excessive gap between the hole itself and the protruding nose or pin, or shows evidence of allowing properly seated factory primers to bulge would be a candidate for a replacement. Primer cup deformation or perforation can cause the gun to lock up, and the escaping gasses and particles can pose a danger to the shooter as well.
Replacement of a defective or worn bushing requires several special tools, including a staking rod with a spring loaded centering pin. (see photo)
Cleaning this area is also critical. A dirty bushing that is impacted on the hammer side with shooting debris, dust and residue will certainly sustain added wear and tear.....and this dirt can contribute added wear to the hammer nose and or frame mounted f. pin as well. Dirt and debris here can also cause misfires and light primer strikes.
Take a look down inside the hammer frame cut at the back of the bushing (or pin) to check for dirt and debris. Use a good light and a magnifier. This area should be periodically and thoroughly cleaned with solvent and a brush, then flushed or blown out with compressed air. Cleaning the firing pin, channel and spring, on guns fitted with the frame mounted pins is also a good idea as this enclosed area can get dirty from regular use.
Also, make sure that the hammer nose or the frame mounted pin, depending on the model, is freely moving. These parts can get "gummy" from old lubricants and dirt.
If you have evidence of "peening" around the edge of the hole in the breech face on the older models fitted with hammer mounted noses, installing a spring loaded hammer nose will often eliminate or, at least mitigate this problem.
As to the OP's question, the bushing's obvious purpose is to support and protect the integrity of the primer. An otherwise properly fit bushing that has a visible excessive gap between the hole itself and the protruding nose or pin, or shows evidence of allowing properly seated factory primers to bulge would be a candidate for a replacement. Primer cup deformation or perforation can cause the gun to lock up, and the escaping gasses and particles can pose a danger to the shooter as well.
Replacement of a defective or worn bushing requires several special tools, including a staking rod with a spring loaded centering pin. (see photo)
Attachments
Last edited:
flintsghost
Member
Cratering of the primer in the cartridge case and flow of the primer back into the bushing are obvious indications of too much pressure in the ammunition. Most times it's reloads that are too hot. Cratering is mentioned in most reloading manuals as an indication to look for when loading. Neither of those things has anything to do with the hammer nose bushing having a hole slightly large.
