300 brass to 338

[Malamute]

I have some 300 win mag brass I'm going to use for 338 loads. Should I use an 8mm expander as an intermediate step first before running the 338 expander in, or just do it in one step? I havent necked up cases much before and wasn't sure if it made much difference in that size step.

Most of the brass is plain Winchester brass. I also have a box of Federal nickel brass, will it neck up alright, or will it flake nickel off to neck it up?

 

[redbullitt]

I havent done this with this cartridge and havent looked up anything about it. BUT I have made a good bit of 260 rem brass from 243 7mm08 and 308. For me, an intermediate step is ALWAYS a good idea as it helps to minimize tension/work on the brass among other undesirable quirks with forming . The 243 and 7 08 were not a big deal, but if I formed it from the 308, it really helped.

Good luck, hopefully someone will chime in with something a little more specific for you.

 

[RentaCop]

I have used 300 Win Mag brass in reloading rounds for my 358 Norma. Main thing is to trim it when necked up and sized. The shoulder will get pushed back in the sizing die. But why bother, 338 brass is easy enough to find. I used a 338 expander as an additional step before the jump to 358. Dont know about nickel though.

 

[Strongbad]

In terms of sheer diameter 300 (.308") will neck up to 338 in one pass without an intermediate die. Just lube the necks and run it through the die and you're done. Now, that being said I'm assuming you're not trying to use 300 Win Mag cases for 338 Win Mag by just necking them up, because it wont work. Your shoulder is in the wrong place and you can't just smash it backwards with a resizing die. Well, actually you can but why would you want to. Otherwise, if you've got some kind of special rig with a custom chamber or you're just screwing around or whatever, the short answer to your question is that you just need to run it through the sizer. Since I don't know what kind of sizing die you're using to neck them up I'll just add this, unless your shoulder angle in 338 die (assuming it's a FL die) is the same, you'll want to adjust the die so that it's not trying to crush the shoulder. A neck die wont have that issue.

Anyway, I know that's a little muddy but with more info on what you're doing I can clarify. After re-reading the thread it looks like Rentacop covered some of that.

 

[Malamute]

I hadn't thought about the shoulder, but it shouldnt be a problem, I've made 308's out of 30-06's without much drama other than a LOT of trimming, and the necks were a bit thick. Forming wasnt that difficult tho, just made a couple progressive short strokes before final full sizing.

The why part is I ended up with over 100 300 mag once fired brass after starting to work up loads for a friends rifle who ended up moving without paying me for the components to work loads up. I don't mind having different brass for some loads so it's easy to ID different loads. They may end up being used for cast bullet loads. Hmm, I'll probably be stuck with them for ages if I use them for cast loads,....

Guess I'll try the nickel brass and see what happens.

Thanks for the comments guys.

 

[jerkface11]

I would do the intermediate step. And if the brass has been fired you should aneal first.