Dimensions for re-sized brass: Shoulder, Below the shoulder, Web

[bsumoba]

Just curious what you ideally want your FL die to size your fired brass down: at the shoulder, below the shoulder (on the body), and at the web area.

Right now, my dies are made and set up up to do this:

shoulder: 0.001-0.0015"
below shoulder (on the body): 0.002-003"
just above web area: 0.0015"

Does this sound right?

 

[Alex Wheeler]

I would not want them sized any less than that. I shoot for .002 at the shoulder and .001 above the base. Also I bump the shoulders back .002" they shoot better with a little room. I do not want to feel the case on bolt close.

 

[gunsandgunsmithing]

I like a little less at the web...around .0005-.0007" and about what you're getting at the shoulder.. .0015" is what I work to have. I have excellent bras life and no bolt click with very stout loads using these dimensions..with and hardly ever trim.-Mike

 

[fguffey]

shoulder: 0.001-0.0015"
below shoulder (on the body): 0.002-003"
just above web area: 0.0015"

Does this sound right?

No, there is a conflict or two standards. It has been repeated over and over it is not necessary for the case to fit the chamber. Then there are those that insist on full length sizing and there is a quote involving a violin case.

And no one ever explains the difference between a case that fits and a case that just rattles around in the chamber, I am thinking someone could come up with a factor or two.

F. Guffey

 

[jr600yd]

Here's my simple answer:

A case that "rattles around" in the chamber upon firing expends energy blowing the case out to the chamber dimensions. This does two things. First, you get fluxulations in velocity and second you get case stretch. Sizing back down to the "rattles around" dimensions will shorten case life a lot.

A case sized correctly to the chamber will expand to chamber dimensions more consistently, have less velocity spread and will have longer life, the brass is not worked as hard during sizing.