swampratt, are you using a concentricity gauge on your finished rounds to determine runout?
I visited neck turning with some LC .308 cases and gained zero accuracy..I turned other .308 cases and no accuracy there..I sorted cases by weight and my 3 foulers were more than 2 grains different in weight and those grouped the tightest of the day..I was scratching my head on that one.
I eventually cut my barrel shorter..it was 24" now 20.5.. accuracy improved and fliers unexplained ones were eliminated..Savage 10FP.
I kept the other cut off end of the barrel and there are 2 grooves that have no wear pattern or marks.. the other grooves have plenty..messed up barrel at the last 1/2". This thing never shot well.
No aviator I am not using one I have thought of getting one though. But the way I see it ,, when I chamber a round that is long and the bullet is colored with a marker there is a point where the rifling grooves touch just a part of the loaded round.
My chamber is not a match chamber..If i send the round up the ramp from the magazine i feel that may make the concentricity out a bit .
If you have a gauge do me a favor and check the rounds for straightness and then fill the magazine full and chamber and extract them all and measure them again.
I have wondered if that tweaks them.
I eventually cut my barrel shorter..it was 24" now 20.5.. accuracy improved and fliers unexplained ones were eliminated..Savage 10FP.
I kept the other cut off end of the barrel and there are 2 grooves that have no wear pattern or marks.. the other grooves have plenty..messed up barrel at the last 1/2". This thing never shot well.
No aviator I am not using one I have thought of getting one though. But the way I see it ,, when I chamber a round that is long and the bullet is colored with a marker there is a point where the rifling grooves touch just a part of the loaded round.
My chamber is not a match chamber..If i send the round up the ramp from the magazine i feel that may make the concentricity out a bit .
If you have a gauge do me a favor and check the rounds for straightness and then fill the magazine full and chamber and extract them all and measure them again.
I have wondered if that tweaks them.
Just a little info...calipers have a .0025" allowable variance. This means they can be off by that much depending on the amount of pressure you apply while measuring. When you are trying to measure down to that tight of a tolerance you should really be using O.D. mics. If you are looking for that type of accuracy, yout need the proper measuring tool to get you there consistently. I'm not trying to tell you your business, just some constructive advice.
I hear ya.
I have used my Micrometer and can duplicate it with my calipers and i check my calipers ID against my Mic.
I have used some other peoples calipers including some reloading name brand ones RCBS or something ,,could have been Lyman. Do not remember.. but those were crap.
My son has a dial caliper and it too is crap..Does not move smooth and Like you stated tolerance growth is evident.
This set i have cost 75 bucks over 25 years ago and After using other calipers i know why.
I build engines and transmissions and this set is the most accurate i have ever used.
Fowler dial calipers are what i am using.
I hear what you are saying.
I have used my Micrometer and can duplicate it with my calipers and i check my calipers ID against my Mic.
I have used some other peoples calipers including some reloading name brand ones RCBS or something ,,could have been Lyman. Do not remember.. but those were crap.
My son has a dial caliper and it too is crap..Does not move smooth and Like you stated tolerance growth is evident.
This set i have cost 75 bucks over 25 years ago and After using other calipers i know why.
I build engines and transmissions and this set is the most accurate i have ever used.
Fowler dial calipers are what i am using.
I hear what you are saying.
A lot of the potential to ruin concentricity depends on the action. I shoot a Rem 700 and it's a push feed type action, as is the wifes Savage Axis. these lend themselves to having the potential to screw with concetricity. Other actions, like the Mauser or CZ are controlled feed actions which don't have the problem.
Anyway, I checked both rifles. the rem 700 win 300WM did push the concentricity out. the Savage Axis did not (it's a 30-06). I don't know why one does and one does not.
I'm in the process of building a mauser action that will most likely end up as a 308. I originally was going to make it a 6.5Gr, but there's just too much that has to be done make the conversion.
Anyway, I checked both rifles. the rem 700 win 300WM did push the concentricity out. the Savage Axis did not (it's a 30-06). I don't know why one does and one does not.
I'm in the process of building a mauser action that will most likely end up as a 308. I originally was going to make it a 6.5Gr, but there's just too much that has to be done make the conversion.
I'm hoping so. It's being built on a WZ.29 Radom action that had been drilled and tapped for a scope some time in it's past, so it has lost all collector value, but the action is super tight and in good shape.
