.338wm from .300wm..brass??

GooseHunterJr · Member Joined: Oct 18, 2005 Posts: 51 Location: Colorado

have a lot of 300Win Mag case. How are they for making 338Win Mag cases by just putting them in the 338Win mag resizing die???? Also, how about 7mmRem mag case doing the same?????

Ominivision1 · Posted: Fri Aug 05, 2011 2:50 pm Post subject: Re: .338wm from .300wm..brass??

GooseHunterJr wrote:

have a lot of 300Win Mag case. How are they for making 338Win Mag cases by just putting them in the 338Win mag resizing die???? Also, how about 7mmRem mag case doing the same?????

I have done this before BUT: There is a difference in case length and where the shoulder starts. So full length resize and trim afterwards. You need to do fire-forming in your chamber as 300 win mag is .100" longer than the 338.

I have done it for my oldest kids rifle but imo its not worth it as the brass does not last over 2 or 3 reloads. Even thou the 300 is the offspring of the 338, it is just to much trouble. See if you can find some one to trade the 300 brass for 338 brass. Very Happy

GooseHunterJr · Member Joined: Oct 18, 2005 Posts: 51 Location: Colorado

I have almost 150 .300WM cases so it may be worth my time, but I may reconsider if someone has some to trade or wants to buy some. I would like to get more than 2-3 reloads on them. I also have about 30 nickel 300wm cases.

fnuser · Posted: Mon Aug 08, 2011 6:37 pm Post subject: Re: .338wm from .300wm..brass??

those nickel ones are hard to form. i think the 7mm idea would be alot easier because your not moving the shoulder as radically as with the 300-338 forming process. Maybe annealing would remedy both the difficulty in forming and get you a couple more reloads?

PaulS · Posted: Fri Aug 12, 2011 10:14 pm Post subject: Re: .338wm from .300wm..brass??

Keep your pressures well below maximum (10%) and neck size after fireforming and you can get 10 to 15 firings easily from any magnum but the H&H.