Concerns about over working brass...

[Lucky6547]

Hello,
So lets say you have a rifle being made in 6mmSLR with a chamber with a .275 neck.

You size/form 243 win Winchester brass with a full length die (non-bushing die) with an expander to 6mmSLR because Winchester brass often gets dented in the plastic bags it comes in. You notice that there is some visible difference between the neck where it used to be a regular 243 win brass and the new neck/shoulder junction. When you measure it, it is about .272-.273 OD where it was a 243 neck, and .279-.280 OD where it is now an SLR neck. So you turn the brass to .272 so that the neck is cleaning up about 80% where it used to be a 243 neck, and 100% clean up at the new neck/shoulder junction for the SLR.

You get curious about how it will be sized now that you've turned the neck...you size the turned brass with the expander still in, and the neck OD measures .270-.2705ish and you think that seems perfect.
Then you get curious again and take out the expander to see what size the neck would be without the expander. This was a surprise...now the brass comes out and the neck OD is .262!
So when I fire the brass (which I haven't yet, gun still being smithed), I expect the fired brass to be around .274ish...then this die will squish it down to .262, then expand it back up to .270ish...so .012 down, then .008 up again...isn't that a lot of work on the brass? Is that excessive? Would you just use this die to form, and get a bushing die to work the brass less? Or try to have this die honed out to a more reasonable diameter?

Thanks,
Ken

 

[XBBR Shooter]

[...] ...isn't that a lot of work on the brass? Is that excessive?

Yup...

Would you just use this die to form, and get a bushing die to work the brass less?

Thanks,
Ken

Yup...

 

[Shynloco]

... get a bushing die to work the brass less?

Thanks,
Ken

Yup! So brass is worked the same and less. Less margine for error and changing in brass when resizing.

Alex

 

[mikecr]

You didn't seem to tell us how thick your necks actually are. What's loaded neck diameter?

 

[Ledd Slinger]

If it's a bushing FL die. Get yourself a .270", .269" and a .268" bushing to play with neck tension and remove the expander ball.

If it's not a bushing die and you have to work the brass .010-.012" every time, youre definitely working the hell out of it, but it will probably be ok, just make sure you anneal every couple firings to avoid getting split necks.

 

[Lucky6547]

You didn't seem to tell us how thick your necks actually are. What's loaded neck diameter?

.272

 

[Lucky6547]

If it's a bushing FL die. Get yourself a .270", .269" and a .268" bushing to play with neck tension and remove the expander ball.

If it's not a bushing die and you have to work the brass .010-.012" every time, youre definitely working the hell out of it, but it will probably be ok, just make sure you anneal every couple firings to avoid getting split necks.

Not a bushing die...ordered a bushing die and seater from Whidden.
Thanks guys