Refoming 7mm rem mag cases to 308 norma mag?

[kilo 1]

Hi all from an addicted long range shooter & hunter, has anybody had any experience refoming 7mm rem mag cases to 308 norma mag ?

[Norton]

Hey Kilo,

I had a very brief foray into resizing 7mm-08 into .308 (not exactly the cartridges you're after but same calibers so bear with me).

A couple of issues I ran into...

1) Lube is your friend. There is some serious potential for brass sticking in the press when necking brass up.

2) One issue I did have was the necks on some of the brass looked like they had stretched in one place in what would have become a split if the necks had gone wider, rather than the whole next expanding evenly.

To be fair though I had a bit of a mixture of 1-3 times fired brass in different brands so it wasn't exactly scientific...

3) Next length also shortened a fraction, but after firing forming that would obviously sort it self out as the neck stretched again. Nothing there to get too concerned about IMO.

Hopefully that's of some help to get you moving in the right directly.

[Aster]

One issue I did have was the necks on some of the brass looked like they had stretched in one place in what would have become a split if the necks had gone wider, rather than the whole next expanding evenly.

Annealing the brass would hopefully sort that?

Not that 2-3 firings is heaps of abuse, but it would have caused those cases to harden slightly, perhaps enough to produce the soon-to-be splits you mentioned.

[Vati]

Have a look at an expanding mandrel too, rather than just a regular 308 norma mag sizing die.

I was reading up on them earlier but lost the fkn link to the article

Short version is that when necking up with a regular sizing die, the brass is a little elastic and springs back to a slightly smaller size that the calibre your sizing up too.

The expander mandrels take this into account so the finished size is more accurate as I understood it.

Hope it helps.

[Wheelbarrow]

1) Lube is your friend. There is some serious potential for brass sticking in the press when necking brass up.

Muscle up champ

[AusC]

1) Lube is your friend. There is some serious potential for brass sticking in the press when necking brass up.

Muscle up champ

Geeez I don't know about that.

I've put a few rounds through the press without the inside neck being lubed by accident, daaaamn some of them were hard to get out, lol.

[kilo 1]

Thanks gents for all the tips, I knew there was some tool for doing it but could'nt think of the name it.. An expander mandrel I'll get on the redding site tonight..I've got a hunded once fired hornady match cases in 7mm rem mag, I'd much rather reform those than shell out about $140 for 308 norma mag cases..I've got plenty of redding resizer lube so should be good to go..
Thanks again for the tips..