I want to reduce the size of the firing pin tip which then I need to bush the hole in the action. I'm talking about a 94 Stevens action. The reason is that I get blown primers which extrude into the firing pin hole. What's the best way to do this?
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I want to reduce the size of the firing pin tip which then I need to bush the hole in the action. I'm talking about a 94 Stevens action. The reason is that I get blown primers which extrude into the firing pin hole. What's the best way to do this?
First, check headspace. Pierced primers are usually caused by excessive headspace. Headspace normally increases on these guns as the pivot pin wears. The easy way to correct headspace on an inexpensive pivot barrel shotgun is to drive the pivot pin out, rotate 180 degrees and reinstall.
Once this is confirmed to be good or corrected to be good, then check firing pin protrusion. Check positive protrusion by putting the hammer in the fully forward position and use the depth gauge on a dial caliper. Firing pin protrusion should be no more than .050". It is obviously long enough to fire the gun. Shorten the firing pin slowly using a file. Flatten the tip until you get within .003" of the desired length then begin to round the edges and dome the tip. This should allow you to finish up at or slightly less than .050" protrusion.
If headspace and firing pin protrusion are good, then check the fit of the firing pin in the firing pin channel. This is much more crucial in a high pressure rifle, with the relative low pressure of a shotgun this isn't normally a problem. Remove the firing pin from the gun, test fit the pin through the firing pin channel on the breech end. It should be an easy slip fit with no or very little felt play. If the fit is excessive, set the receiver up in the mill, centering the chuck over the firing pin channel.
- Use a center cutting tap, drill just though the thickness of the receiver. You can now either tap the hole (probably not necessary and definitely difficult due to shallow hole) or decide to press fit the bushing. There should be a bit of a lip at the bottom of the hole to seat the bushing against.
- Turn a bushing close to size, within .003" on the lathe, getting set up for press fit. Or, if you chose to tap the bushing hole on the receiver, turn it to size and thread. Make sure you turn enough bushing for a few bushings for trial and error.
- Leaving the bushing in the lathe, measure the diameter of the firing pin, drill a hole to size matching the firing pin. Test firing pin fit. You can either polish the firing pin or the firing pin channel in the bushing.
- Leaving the bushing in the lathe, polish the bushing to the same diameter as the bushing hole.
- Part a bushing off in the lathe, close to the thickness needed. Finalize thickness with file work or sanding across a flat surface.
- Press the bushing into bushing hole, you can use a bit of permanent loc-tite to help secure the press fit bushing in place. Once the loc-tite cures, if the bushing is not flush with the breech face, polish the bushing flush to the breech face, being careful not to remove material from the breech face or you might wind up with a headspace issue.
- Do a final test fit of the firing pin. If the bushing was oversize, the channel could have been compressed a bit. Polish as necessary, reassemble and test fire.
Having said all that, I believe it is a headspace issue.
Thanks a bunch I'll print that out. Thanks a lot.