#13 Postby williada » Sat Dec 22, 2018 8:56 am
Just adding to Ben's comments about a having an old 30 cal re-chambered and barrel length. Extreme long distance is a class of its own and if you want to be successful Lee unfortunately you have to run with the best gear to be competitive. An old barrel might have to sacrifice valuable inches. But there is an additional problem unless sufficient setback is made the new reamer will follow the old chamber. If the new chamber is bigger, then a boring bar set up before chambering can correct the issue. If there was misalignment, the outcome would be in-bore yaw for the projectile.
Commonly, using the same chambering, the throat is so eroded at six o'clock the piloted reamer will follow this deviation. If people have had a setback, just get a bore scope and see if the fresh cuts are round and not oval. If they are oval you can bet on the misaligned bullet slap wear leading the new reamer astray. That's why a barrel should not be left with a high round count for setback unless the gunsmith is highly experienced in this operation. This is more a problem for loads that are not jammed because they sit in the chamber if fully resized at the six o'clock position and so create the wear on ignition. Neck sizing avoids this problem particularly with collet dies. It is the reason why those in the know nip their chambers back about the 800 round mark and commonly re-crown ever 400 with just a touch up to maximise barrel life and performance. I often use my chamber reamer to scrape out just the carbon deposit with just a twirl of the fingers. Much better than trying to scrub out with paste a creating more problems.
A few guys where I live have replaced the Savage actions and their scores have improved for the long stuff. It all depends on how serious you want to be. Shooting the real longs just for fun is a great experience in its own right. I have never been a fan of switch barrels because there a few inconsistencies at the pointy end of harmonics getting it right each time a barrel is drawn up. This matters at the longs. At 1500 yards every little margin counts as we know right down to velocity numbers with a few feet a second spread.