Home Forums Reloading Big Game Rifles Turning 7mm RM brass into 257 WBY

I saw it posted somewhere a little while back that this could be done and wanted to give it try. So I get my 7mm brass(Rem.) and fl size it with the Redding die and get an indentation below the shoulder radius. I start backing off to try and get rid of this indentation but it will not disappear unless I back off so far that the brass isn't getting properly sized. I don't believe it to be a hydraulic type dent resulting from excessive case lube.

Are these slight indentations(ring-like) to be expected or is it the brass or something else?

Should I just work up loads as normal and shoot? Will the load that shoots best shoot differently the next time I load these same cases? Will this fix the problem or is it a no-no?

Anyone who has experiece with this(or something similar) please chime in. Thanks in advance.


Nail

if you set dies so cases will just chamber in your 257 w do you still get dents in case, setting dies so they touch shellholder is not needed or wanted for that matter
ed in idaho

1234, I did back off till the dents went away but it didn't look to be getting the neck and shoulder radius formed enough. I also didn't try one to see if it would chamber and am away from where the brass/reloading bench is to try it right now.


Nail

I have formed hundreds of both 257 and 270 Wby from 7mm Rem Mag without a hitch. Just do as 1234 has said and size the brass until the bolt barely closes on the reformed brass.

Set the lock ring on your die and go to it!

Ted

10-4. Thanks guys.


Nail

BE SURE TO USE VIRGIN BRASS!! I tried it with once fired and it was really tough. First off the virgin brass has smaller dimensions. Once you blow the shoulder forward and toughen up the brass with the first firing it gets alot tougher to reshape them.

X2 I find the same senario. I do have my RCBS resizing die touching the shell holder and have no problem with dents or anything else.