Neck tension, accuracy & you....

[jhelmuth]

To "measure" neck tension, first measure the neck OD after sizing, then measure thhe neck after seating. Sbutract the two - this is considered the neck size. In selecting neck sizing bushings, you want to seat a/the bullet in the neck of the case you intend to use and measure it. Then subtract the amount of neck tension you want (take into account about .001" for spring back). This is the bushing size you want.

To MZ5s point (earlier), I don't think you can really get more that 0.002 tension as the bullet will cause the neck to strech at some point. In my own mind, I don't want more or less tension, I want consistent tension and only enough to do the job. Streching the case neck (after having squeezed it in the sizing operation) is simply working the neck more than necessary and potentially creating consistency issues.

[skypilot]

Frank, I try to stay .002" on the neck tension, which is the same as I used while load developing @ incremental distances. I try to alter only the seating depth, after finding a nice load.
I only neck size using Lee dies until I have to FL resize.

[lal357]

mz while i agree with your statement the thing i noticed mostly with my 308's is when i went .003 under on the bushing my sd's got lower i contribute that to the bullet having a tighter fit/resizing it when it is seated .it doesnt do it with all my cases just the 308 lapua i use on my 223 i go .002 under one thing like i stated above is i want to try neck turning to get my necks more uniform in thickness.