"By dialing in one end at a time I can compensate for the curved bore and get my chamber, perfectly in line with the "bore". (throat to 2 inches farther) To overcome the curve in the bore where the chamber is I have to single point the chamber area to bring it inline with the throat and 2" farther in area that the barrel is dialing into. Otherwise the reamer will just follow the curve in the bore and make the point of dialing in on the throat and 2" into the bore pointless.
This gets the bullets straight into the throat as possible"
HG, i was wondering if you find any measurable curve in the 2" of bore that you dial in? it make sense to me to dial in the area where you are working as that is where the bullet will seat.
what doesnt make sense to me is the need to single point cut. id imagine that the curve in 2" would be at unmeasurable so the bore should be running true to the lathe spindles center. that should mean that you could just ream the the chamber with reamer and it should turn out square.
The other question i had was when you single point cut how deep do you go. if you went the full chamber depth (minus a little for the reamer) then the shoulder of the reamer will be the first thing to bear as you insert it instead of the bushing on the end in the bore.couldnt that lead to some miss alignment?
thanks for sharing your knowledge and thoughts guys
I can measure over 6" up into the bore and do it in tenths. When you measure in tenths any amount of curve looks like a lot considering I hate to see the indicator moving at all. So measuring in tenths it depends on the barrel but most every barrel has quite of bit of curve in 2". I have never seen one perfectly straight. To do the Chey Tac based rounds we have to be able to single point close to 2.5". Cutting to the base of the shoulder to .010" under gets the pilot into the bore long before the body gets much cut. The bushing is close to 1.5" beyond the shoulder on a 338 LM.
__________________ Some kids want to be a fireman or a doctor to help people. I wanted to be a gunsmith.