reset sizing die when changing brass brand, lot, etc?

[Ray123]

I use alot (thousands) of range brass from every manufacturer in the world it seems in 5.56, 300 blackout, & 308 auto loaders ..and they shoot accurate enough and always go bang...but I'd prefer they all be LC brass or commercial, but they're all mixed together. I machine the set back gauges, and test with a cartridge gauge and a drop indicator on a granite surface plate for variation with a variety of brands...they bounce around an easy .003 on set back, after determining where the mean average is I size a bunch like a thousand in one setting. Same with 50 BMG LC cases except they are skim neck machined in a lathe, as are primer pocket crimps, I do 200 cases at a time ...trimmed to length champhered inside and out one operation in the Bridgeport mill and dead length collet...now the 50BMG is capable of 5 shot MOA (and sometimes close to 1/2" MOA with 5 shots but rarely)with 647 FMJ or APIT military surplus bullets, (but not the ones with heavy pull marks, they usually do okay with 1.5" area) especially if you weigh brass and powder charges...but I don't usually weigh the brass, just the powder, life's too short and I'd rather shoot than weigh, since there is no competition going on with pulled bullets...just fun.

 

[Webster]

Rigidity of press and technique could be an issue.
I have two variations of brass for my 22 Nosler.
Heavy/thick 6mm Hagar sized to 22 Nosler and Nosler/Dogtown brass.
Press is a 4 hole Lee operated without indexing. Not the best but no cam over.
When bumping the Hagar brass I go slow, pause, and bump to the stop again.
I get the same measurement as the nosler.View attachment 1352081

 

[Webster]

Never understood how press rigidity or cam over is an issue. If the bottom of the die touches the shell holder it’s impossible to push the case in farther. Same thing with cam over. Don’t want to get in a P match on cam over. I do my thing and I shoot small groups. Nothing to worry about.

 

[Cfshooter]

I do not know if you will need to or not, but I check and measure bump every time I set up to size.

 

[4xforfun]

I didn't read all 11teen posts, but if your die is set up for your chamber and the correct bump, what could possebly change?? If the brass is thicker your die will simply push it to the INSIDE of the case. If it is longer...it will push it back Now, tweaking the load, neck tension, brass length may well be necessary, but not the die. Once set.....lock it and throw away the key till you get a new bbl/chamber.

 

[Dusty Stevens]

I didn't read all 11teen posts, but if your die is set up for your chamber and the correct bump, what could possebly change?? If the brass is thicker your die will simply push it to the INSIDE of the case. If it is longer...it will push it back Now, tweaking the load, neck tension, brass length may well be necessary, but not the die. Once set.....lock it and throw away the key till you get a new bbl/chamber.

Not at all the case from my experience. Just say you set it up on once fired brass in your chamber, 2 firings later it gets harder and doesnt take a set as good as new brass then you got a tight fit on half your cases. 3rd firing even more get tight and some you gotta beat the handle closed. This is why they sell different gadgets to ease in sizing die adjustment such as the jlc clicker on arkco’s hood press, the pma die adjuster and the click adjust whiddens. Its very necessary to adjust your sizing die frequently.

 

[4xforfun]

Not at all the case from my experience. Just say you set it up on once fired brass in your chamber, 2 firings later it gets harder and doesnt take a set as good as new brass then you got a tight fit on half your cases. 3rd firing even more get tight and some you gotta beat the handle closed. This is why they sell different gadgets to ease in sizing die adjustment such as the jlc clicker on arkco’s hood press, the pma die adjuster and the click adjust whiddens. Its very necessary to adjust your sizing die frequently.

I guess I haven't had this problem. Most of my 1k/600 match rifle tubes have their own BODY die because I switch BBL's quite regularly. I got used to taking my bolt apart and checking headspace when I had only one die and continue to do the same even though each BBL has it's own die now. Same with my play and hunting guns. All tubes have their own body die and I haven't had to tweak them.....YET!!

But, I will admit that in the grand scheme of things, I am a newbie compared to you....

Tod