Hide thoughts about FL resizeing vs. bump shoulder?

[greybeard]

Since I have a need to review my reloading practices, I compared the length of FL sized brass to fired brass, ( measured from the base to a datam line on the shoulder), there is a .015 diffrence. is this too much? Had always set up the sizeing die by instructions to bottom die out on the shellholder.
The brass ,LC matching year, was fired in a AR10. Thinking of bump .005, will this still feed reliable? What say all? Any accuracy advantages from watching the bump? Know this should make the brass last longer?
First step of my reloading review. (double checking to run the gremlins out of the reloading room), possibly got careless on some of the small stuff, never checked this before)????.

Getting ready to start a new load work-up 178gr or 168 gr A-Max, got box of both. hope to use MR2000 powder.

any comments?

Edit:

Thanks all!

Idea to adjust the sizeing die is to use a stack of shim stock between the shell holder and the die, to take up the .010 to .012 too much I bumping the shoulder back. load a dummy round to check feed and chamber.

Will look at polishing the expander ball.
After reading the reloading stickies, again, will do a little more work on the brass prep.

 

[ZiaHunter]

The difference of .015 between FL and fired brass is excessive. For a gas guns it is generally recommended to set the shoulder back .003 to .005. The .015 will greatly reduce case life and could possibly lead to case failure. For setting up dies on gas guns I have found the RCBS Precision Mic to be the most accurate. Also I would recommend getting a case gauge to verify proper sizing.

 

[roggom]

What are you using to measure your HS? I have the redding S bushing full length sizing die and full length size and only bump a few thou. Measured with the RCBS precision mic. My point is you can do both if you have a good sizing die and a proper means to measure.

 

[mkollman74]

Are you getting any chattering or drag when you are pulling the button back through the case mouth?

 

[VKC]

In my opinion, you should FL resize for all semiauto rifles. You should only neck resize for bolt guns.

 

[Casey Simpson]

He knows his fired dimension and his set-back dimension. Its 15 thousandths, he wrote. He's asking if that's too much. Zia answered the question.

Size cases without the expander ball.

Actually, de-cap cases in a separate step, step one. Re-size cases; step two. Expand mouth; step three.

Expanding by entering the case is the right way. Expanding while entering may produce ammunition that is more accurate. Expanding while entering avoids stretching the case mouth out of whack. Also, expanding by entering the mouth with the button or mandrel is better because lubricating the mouth works best this way. Otherwise, the expander leaves lube in the case's shoulder that got squeezed off. Polish the expander whether its a button on the decapping stem, or a mandrel.

 

[greybeard]

edit in original post, bump