Brass necking down then back up ?!?

[tuffbuff]

I have a new to me issue.

Bought some 8mm mag brass, some are fired and some new. Of the 50 new, 36 are primed and necked down to 7mm ( didn't check and seller didn't mention) this is new virgin brass.

Is it ok to neck back up and use as normal? I did one and looks ok, just slight ring mark you can see where the die quit on the 7mm neck. It feels smooth with my finger nail and chambers fine in rifle. Hornady one shot lube couldn't handle it so I dug out my old RCBS case lube and brushed some in and a little bit on outside of neck with finger and went ok.

Has anyone ever done this or something like it before? Brass has got to go somewhere, it's a fairly decent jump from 7mm to 8mm. Just load em with a starting type load as a precaution? Or should I just sell these suckers.

 

[burnt_servo]

i do that on a regular basis without issue with a few chamberings .

it can work harden the brass if done more than a few times and it can also cause the brass to stretch a little .

if you suspect the brass has been worked enough to be work hardened , annealing will make things right again .

you should have zero issues resizing back to 8mm ..... just make sure you use lube .

 

[Eagleye]

If you feel that 7mm to 8mm is a big step, just run a 30 cal expander button through the neck first, then do the 8mm trick.
I also have an 8mm Rem Mag, and regularly make brass from 7mm STW and 300 Weatherby brass. [The latter goes easy] D.

 

[c-fbmi]

Absolutely nothing to be concerned about. You could just load them with a good 7 STW load and 7mm bullets and fireform them as well, they come out perfect. I personally believe the necks stay more concentric with fireforming but have also done the expander thing as well. Made most of my 9.3X62 brass by expanding 30-06 and 35 Whelen up to 40 cal and then necking back down to 9.3, works every time.
No need to get rid of the brass there are several accepted methods of bringing it back to 8mm RM spec. It's only brass......it'll do pretty much anything you tell it to do......after more than 40 years of wildcatting I can fully attest to this.

 

[tuffbuff]

Will give er a go then, being new brass shouldn't work harden yet I'd think. I don't have any 30 stuff on the place - don't need to with the Big 8

Also first time punched a couple dozen live primers, safety glasses and ear plugs, lol. All went well.