Different bushings throughout case life?

[arthurj]

Most people reading this will probably say "Duh, are you just now figuring this out", but the answer is yes I am just now figuring this out. So to my understanding as a case is fired throughout its life the same bushing will have different effects on it due to the spring back quality. This will lead to a gradual decrease in neck tension as it is fired and sized again. I have been finding that my cases that have been fired 5 or 6 times, I can tell a big difference in the seating effort. I think that the lower neck tension is helping my groups. Do you guys step down your bushing size at different points in a case life? If you do does it seem that about every 5 firings a bushing .001 smaller is needed? I guess the best way to know is use a mic to take readings at different points to check the tension.

 

[USSR]

[ QUOTE ]
I think that the lower neck tension is helping my groups. Do you guys step down your bushing size at different points in a case life? If you do does it seem that about every 5 firings a bushing .001 smaller is needed?

[/ QUOTE ]

Have also found that lower neck tension leads to smaller groups (all other things being equal). That's the beauty of bushing dies; the ability to readily adjust neck tension between different brass and over the lifespan of brass.

Don

 

[Mysticplayer]

more important to anneal your brass and keep the same bushing size. Brass work hardens at varying rates. You will find that soon, you will get weird groups and flyers even though everything is the same.

Work up with less neck tension if that is better but keep it the same amount. anneal the necks to maintain that consistency.

Jerry

 

[arthurj]

Thanks Jerry I have been dreading the annealing process! I've glanced at some posts about it, do you mind sharing your method of annealing?