brass sizing question

[swadiver]

not knowing the metallurgical properties of brass, my question is; is it necessary or desirable when doing any sizing operation, ie neck, body, or both, to leave the ram up in the sizing position for a delay of a few seconds to allow the brass to form properly and not spring back, or is this delay unnecessary?

let's hear it

 

[shoot4fun]

IMO, it is unnecessary to leave the brass in a die to "set" it.
Properly annealing is the key to the die doing what you want it do do to the brass.
As brass hardens (from working it) it becomes less receptive to "staying put" so to speak and it will reset itself once removed from the die. That will cause inconsistent shoulder bump and neck tension.

 

[MrBottleneck]

Here some interesting reading for you Swadiver.
http://forum.accurateshooter.com/th...t-have-an-effect.3769977/page-3#post-35978995

 

[T-shooter]

not knowing the metallurgical properties of brass, my question is; is it necessary or desirable when doing any sizing operation, ie neck, body, or both, to leave the ram up in the sizing position for a delay of a few seconds to allow the brass to form properly and not spring back, or is this delay unnecessary?

let's hear it

Probably unnecessary. I've tried running older brass and leaving it up for even a few minutes, or running it through the die several times. Usually, it didn't matter, it sprang back anyway. If the case isn't getting resized properly, it needs to be annealed. I just used a box of 50 new match cases that I had to anneal. I always neck turn and then run everything through my Forster full length die first to equalize them. The runout on a fired case, or a good case, is usually no more than .001" in the middle of the neck. These were .004" to .009". Resizing a second time didn't help. After annealing, resizing, and neck turning again (it only removed metal less than 1/8" from the shoulders where they were pulled back inline. Now almost all are at or under .001" and maybe 10% are between .001" and .002". When annealing, I put the heat on the shoulder area.

 

[swadiver]

thanks. i do anneal, btw. this question is as much a theoretical question as a practical one.