Quote Originally Posted by 1903Collector View Post
Im unsure of the typical barrel thread pitch
Square threads on the 1903, 10 per inch I think, with grooves at 0.051 wide. Yes. google doesn't lie

Quote Originally Posted by 1903Collector View Post
When I cut a short chambered 1903 barrel I have to be VERY careful not to take too much off.
even more careful on an old barrel that appears to be short. Even just a little leftover jagged edges from surface rust on the chamber's shoulder can throw off your go gauge. On new short chambered barrels, it usually takes me 5-20 turns. As such, I make one turn without any downward pressure just to clean out any possible edges left by the rougher, then I take it 2-3 turns at a time with very very light pressure. There is no reason to press down noticeably when finish reaming by hand. Use plenty of cutting oil, clean everything out every 2-3 turns when you check your progress.

setting a 1903 barrel back would require a full turn taken off the shoulder (so ~0.100), and then the same amount taken off the breech face, extractor groove deepened, etc.