rockrat
12-29-2015, 08:08 PM
LONG.
I am no gunsmith by any stretch ,but I do tinker and have put on a few barrels over the years, on my guns.
You hear the saying " measure twice, cut once" , well it should be "measure 10 times, cut once"!!
Bought a couple Shaw, pre-chambered barrels, the 8mm mauser went OK, but after a couple of years, finally decided what to do with the 7mm BR barrel I had on the shelf.
We shoot, at our range, a varmint silhouette match, every month in the warmer parts of the year. I have shot my xp100 I rebarreled to 22-250, but just not enough HP, so been shooting rifles for the last few years, but really like my XP's. Was going to put on a 243 barrel, but decided on the 7mm BR.
Started on it yesterday afternoon. Got out my depth mike, my micrometer, calipers, ect and started measuring. Figured out what to do and stuck the barrel in the lathe and cut. Installed barrel, bolt wouldn't close. Hmm. rechecked measurements, still no go. Gave up, came inside and watched football.
Went back out this morning, measured again, everything looks good. Bolt still won't close. Cat wants attention and is bugging me, cat gets tossed outside. Cut a few thousandths off chamber end on recess and thread length. Bolt still won't close. Look for Dyekem(sp?), remembered knocking it on floor years ago, go into town to try and find some. FINALLY, find some, head home. Pull barrel off of action (again, for the umteenth time), put dyekem on, reinstall barrel, work bolt. Pull barrel off again. Maybe a little smeared off of end of chamber end. Cut about .010 off, do all over again, bolt still won't close. look at parts and think "dimension on one of the parts I have written down does't jive with the MKI eyeball. Pull out calipers for a quick measurement. WHOA!!!
I am about .026" off what I have written down. Pull out micrometer, looks OK, then I look closer. I read the micrometer wrong, I was off by one mark (.025":oops::veryconfu). No wonder the bolt won't close!!!
Now things make sense. Re-do measurements, recalculate, re-cut chamber end of barrel, bolt closes!!!:bigsmyl2:
About 3 hours down the tube so far. But guess what, after all that cutting, the deep chambered barrel is now a shallow chambered barrel!! I need to re-cut the chamber. Luckily, I had ordered a 7mm BR reamer from Midway a few weeks ago and it came in the day before Christmas. Barrel back in lathe to deepen chamber. Cut a little, clean and remeasure and calculate how much more I need to cut. Re-cut, check headspace, way off, too deep now, sigh!!. Must have had a shard of metal in the chamber when I put my gauge in and threw off the measurement. Recut some off shoulder of barrel, reinstall, measure, recut. Do this 4 times. About .012" alltogether
Finally got it headspaced. Now to polish a bit, put a little cold blue on it, cut off the barrel to length and crown. Going to make the barrel about 20" long, kind of like one of those long range handguns I have read about. Gun looks strange with its funky aluminum stock. Action is clamped in the stock.
Bad thing is, too cold to go to range to shoot the thing, not supposed to get above 25 degrees all week. At least its almost done. Will be interesting to see just how it shoots.
Can't wait till the matches start, going to suprise a few guys out there with it. If that does't work, I also got in a 30-223 reamer and may have to have a switch barrel gun.
I am no gunsmith by any stretch ,but I do tinker and have put on a few barrels over the years, on my guns.
You hear the saying " measure twice, cut once" , well it should be "measure 10 times, cut once"!!
Bought a couple Shaw, pre-chambered barrels, the 8mm mauser went OK, but after a couple of years, finally decided what to do with the 7mm BR barrel I had on the shelf.
We shoot, at our range, a varmint silhouette match, every month in the warmer parts of the year. I have shot my xp100 I rebarreled to 22-250, but just not enough HP, so been shooting rifles for the last few years, but really like my XP's. Was going to put on a 243 barrel, but decided on the 7mm BR.
Started on it yesterday afternoon. Got out my depth mike, my micrometer, calipers, ect and started measuring. Figured out what to do and stuck the barrel in the lathe and cut. Installed barrel, bolt wouldn't close. Hmm. rechecked measurements, still no go. Gave up, came inside and watched football.
Went back out this morning, measured again, everything looks good. Bolt still won't close. Cat wants attention and is bugging me, cat gets tossed outside. Cut a few thousandths off chamber end on recess and thread length. Bolt still won't close. Look for Dyekem(sp?), remembered knocking it on floor years ago, go into town to try and find some. FINALLY, find some, head home. Pull barrel off of action (again, for the umteenth time), put dyekem on, reinstall barrel, work bolt. Pull barrel off again. Maybe a little smeared off of end of chamber end. Cut about .010 off, do all over again, bolt still won't close. look at parts and think "dimension on one of the parts I have written down does't jive with the MKI eyeball. Pull out calipers for a quick measurement. WHOA!!!
I am about .026" off what I have written down. Pull out micrometer, looks OK, then I look closer. I read the micrometer wrong, I was off by one mark (.025":oops::veryconfu). No wonder the bolt won't close!!!
Now things make sense. Re-do measurements, recalculate, re-cut chamber end of barrel, bolt closes!!!:bigsmyl2:
About 3 hours down the tube so far. But guess what, after all that cutting, the deep chambered barrel is now a shallow chambered barrel!! I need to re-cut the chamber. Luckily, I had ordered a 7mm BR reamer from Midway a few weeks ago and it came in the day before Christmas. Barrel back in lathe to deepen chamber. Cut a little, clean and remeasure and calculate how much more I need to cut. Re-cut, check headspace, way off, too deep now, sigh!!. Must have had a shard of metal in the chamber when I put my gauge in and threw off the measurement. Recut some off shoulder of barrel, reinstall, measure, recut. Do this 4 times. About .012" alltogether
Finally got it headspaced. Now to polish a bit, put a little cold blue on it, cut off the barrel to length and crown. Going to make the barrel about 20" long, kind of like one of those long range handguns I have read about. Gun looks strange with its funky aluminum stock. Action is clamped in the stock.
Bad thing is, too cold to go to range to shoot the thing, not supposed to get above 25 degrees all week. At least its almost done. Will be interesting to see just how it shoots.
Can't wait till the matches start, going to suprise a few guys out there with it. If that does't work, I also got in a 30-223 reamer and may have to have a switch barrel gun.