.358 Winchester - .308 brass work OK?

[Jeff/1911]

Hi Folks,

I've heard this before- that.308 Winchester brass works OK for forming into .358 cases just using a regular sizing die...can anyone here expand upon this for me?

Thanks, Jeff/1911.

 

[prosper]

If it's anything like the 35 whelen - and I see no reason why it shouldn't be - it's just as simple as running 308 brass into a 358 FL size die. The brass will probably come out a bit short, but not enough to worry about - plus you won't need to trim it

You shouldn't have to do any sort of annealing or incremental sizing unless you start running into a lot of split necks (you shouldn't have many if you're using new unfired brass). If you DO though, you could get a 338 Federal die and size up in two stages, or anneal the necks

 

[bjjzak]

I did a few hundred 308 to 358 cases just by sizing up. but beware some brass is thicker in the neck area than others. For example, had some Norma match brass, and these will not work when done this way, With the extra thickness, you wind up with a double shoulder, no matter which combo of dies I tried it just wouldn't work. I think I still have 50 or so kicking around, done on federal or winchester brass (worked great!), pm me if you're interested and I'll have a look see.

Blaine.

 

[Why not?]

I have done a pile of 308 to 358. One pass through the full length sizing die and you're ready to load.

bjjzak is right about the bottom portion of the new neck being thicker than the rest of the neck. This is because that part is formed from what was originally the shoulder area of the case. The cases will still chamber in the rifles I load for, but you may have the same problem he has had if your chamber has a tight neck.

Just give it a try and get back to us...........and don't forget to lubricate the inside of the 308 necks before you neck them up. Not only does it make the job easier, but the necks will be more uniform.

One more thing, when you neck cases up this way, they are already the correct size and do not need to be fireformed. Just load and go!

Ted

 

[A-zone]

Lube the inside of the neck and, if you can, use a tapered expander, like the Hornady .35 cal neck-sizing die. That's a lot smoother than the RCBS one.

Do you have a set of dies for your new toy?

 

[Why not?]

My RCBS 358 Win die came with a tapered expander. They must anticipate folks necking up 308 Win.

Works very slick!

Ted

 

[bigbull]

Lube the inside of the neck and, if you can, use a tapered expander, like the Hornady .35 cal neck-sizing die. That's a lot smoother than the RCBS one.

This is great information, I have done a bunch of 358 brass from 308's and have generally had very good results, you might get the odd crushed case or split neck but that is to be expected. I personally would not reform brass unless there was used cheap brass on hand, if buying new brass it pays to pay the extra money that the 358 brass costs and save yourself the hassle. The other problem I have experienced is that the necks seldom expand equally and you will experience uneven neck thicknesses, this can be cured by taking a fine skim cut of the necks, and again don't be afraid to use enough lube in the necks.
bigbull

 

[Rick]

I've heard this before- that.308 Winchester brass works OK for forming into .358 cases just using a regular sizing die...can anyone here expand upon this for me?

Yeah, but considering how cheap bags of Winchester .358 brass are, I'm not sure why anyone would bother. I just buy a 100 empty cases; I can always spend the time I save on primer pocket uniforming and whatnot, if I want to spend some time messing around with brass.

But if you enjoy the process or need to save every dime possible, go for it...

 

[Jeff/1911]

A-Zone - Yes, I bought some the day I got the rifle...Thanks.

Thanks guys. I have started off by buying some new .358 cases...I tried a couple of .308 Win cases and they resized fine. I have a ton of once fired .308 brass - hence the question.