300wm brass
- Thread starter bigjohn24
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Is your question if it is POSSIBLE to make this work?? If so it is POSSIBLE but I wouldn't recommend it. As I'm sure you're aware the shoulder of the 300 win mag is well forward of the shoulder of either the 7 rem or the 338win. This means you will have to either hydraulically blow the shoulder forward or fire form to move the shoulder forward Simple case forming won't move the shoulder forward. IMHO the success rate will be pretty low and the resulting brass that does survive the process will likely only be usable in the 300 win once or twice as it will be thin just ahead of the belt from moving the shoulder that far forward. Just my opinion, but I wouldn't mess around with it, too many chances to mess up and ruin a good rifle with a split or ruptured case...YMMV
Kevin Thomas
Well-Known Member
BigJohn24,
NO! The 300 Win Mag case is longer than either the 7mm Rem or 338 Win Mag. Case length on both the 7mm and 338 Mags is 2.500", while the 300 Win Mag measures 2.620". You'd wind up with a case neck only about .140" in length, far too short in a case that's already considered to have a very short neck. You can do it the other way and form the 300 down to either the 7mm or 338 (but I'd suggest that you'd have to be really, really bored to do this) by bumping the shoulders back, necking up or down as the case may be, and then trimming to length.
This stuff isn't exaclty uncommon, or hard to come by, even in the crazy times we have right now. I'd save the case reforming for more extreme instances wherein the case in question can't be procured in any other manner. Trust me, it's a last resort.
NO! The 300 Win Mag case is longer than either the 7mm Rem or 338 Win Mag. Case length on both the 7mm and 338 Mags is 2.500", while the 300 Win Mag measures 2.620". You'd wind up with a case neck only about .140" in length, far too short in a case that's already considered to have a very short neck. You can do it the other way and form the 300 down to either the 7mm or 338 (but I'd suggest that you'd have to be really, really bored to do this) by bumping the shoulders back, necking up or down as the case may be, and then trimming to length.
This stuff isn't exaclty uncommon, or hard to come by, even in the crazy times we have right now. I'd save the case reforming for more extreme instances wherein the case in question can't be procured in any other manner. Trust me, it's a last resort.
Lefty7mmstw
Well-Known Member
Even the 300 win to 7rem thing isn't a good move; I tried this for some test loads once when I had most of my 7rem brass loaded but had some scab 300 win brass lying around. The necks all had little wrinkles at the neck/ shoulder juncture and I had to bottom out the die to get them short enough to chamber.
