Early last year (before I purchased my own small lathe) I had a fellow make me a repeating breech for an airgun project I was working on. Overall, he did a pretty nice job except for one detail - instead of drilling the 1/2" hole the entire length of breech in one shot, he drilled in from both ends (said he didn't have a long enough bit) and as you probably already guessed, the two holes don't line up perfectly. Barrel section is dead-on straight with dovetail rail so that's good, but bolt section is off by about .015" - .018". I attached a photo for your viewing pleasure showing the offset between bolt/barrel....
Between being super busy at work and having numerous other projects on the go, I tossed the breech on a shelf and pretty much forgot about it until now.
Breech is basically useless in its current form, but rather than scrap it and start over, I'm going to try and fix it if possible. I have a 10" long 1/2" bit here now so I was thinking(?) of boring/drilling the rear section of breech out to 5/8" or so, plugging it with a length of aluminum round bar held in place with high strength retaining compound, then re-drill it with my long bit coming in from muzzle end to keep everything in line. Also going to sleeve the bolt section of breech with some thin-walled brass tubing for a smoother action while cycling the bolt. Then just re-mill the excess aluminum/brass out of the bolt handle and hammer pin slots.
So my question is - is this the right way of fixing the issue or is there a better way? I was just going to go ahead and do it, but thought I better ask someone first who would know better just in case I'm missing something.
Thanks for any advice/tips you can offer!
Between being super busy at work and having numerous other projects on the go, I tossed the breech on a shelf and pretty much forgot about it until now.
Breech is basically useless in its current form, but rather than scrap it and start over, I'm going to try and fix it if possible. I have a 10" long 1/2" bit here now so I was thinking(?) of boring/drilling the rear section of breech out to 5/8" or so, plugging it with a length of aluminum round bar held in place with high strength retaining compound, then re-drill it with my long bit coming in from muzzle end to keep everything in line. Also going to sleeve the bolt section of breech with some thin-walled brass tubing for a smoother action while cycling the bolt. Then just re-mill the excess aluminum/brass out of the bolt handle and hammer pin slots.
So my question is - is this the right way of fixing the issue or is there a better way? I was just going to go ahead and do it, but thought I better ask someone first who would know better just in case I'm missing something.
Thanks for any advice/tips you can offer!