Can 358 win brass be made by necking up 308 win brass, or would that cause too much stress on the neck. If it can should it be done in a couple steps. ie 338 first. Or should I just buy 358 win brass off the internet? I can't find any locally.

I don't have a 358, but I have had some problems going from 308 to just 338 Federal with Win brass. The necks worked great for the first firing by just sizing in the FL RCBS 338 die, but the necks wouldn't size down enough to give any neck tension after they were fired in the 338 Federal. You could size them and the bullets would just slide in by hand as the brass had thinned. I bought some cheap boxes of the Fusion ammo for the brass which worked great for several firings and haven't tried the 308 brass again. I think I'll give some thicker 308 Federal brass a try to see how it works. I could have run them into a 308 neck die and then back into the 338 die, but it seemed to be a good bit of working the brass and time consuming as well.

Intrested to hear what others have found for the 338 Fed and the 358 Win.

Reloader

Ckemp,

I had absolutely no problems forming 358 Win out of rem 308 cases...I used a Redding FL size die and used plenty of sizing wax.

I have re-loaded and shot the 358 cases about 6 times and have had no neck tension problems.

I really enjoy my .358 win and have had great accuracy from the 220 gr speer flat nose bullets and 47 grs of IMR4320.

Good luck!

Thanks for the replies. OK here's where I start to sound like a rookie. I've reloaded for a couple of years for my 243, 270 and 338. I've even necked down some 30-06 brass for my 270 win and that worked perfectly. I've never necked anything up, though. How do I go about doing this. Do I just run a 308 case through a 358 win die, or is there a die specifically for necking up this brass? I'd think that if I was to just put a 308 win case in the 358 die and try to run the expander ball through I'd have to push pretty hard and crush the case. Thanks.

You need a FL die with a longer tapered expander button. Some .358 FL dies come with the tapered expander. If not you need to buy one or buy the Lee universal expander die. Redding also makes tapered expander buttons to fit their dies and they fit several other brands as well.

If you want to take the less expensive road you can simply put an appropriate screw in a drill chuck screw on the expander button and sping it against a griner or belt sander to form a taper on the end of the button. Polish all grind marks out when the taper grinding is completed.

Thanks for the reply. The universal expanding die sounds like a good idea. I'm trying to picture how this would work, though. Does the universal expander button just flare the mouth of the case and then you use the regular 358 resizing die? I imagine the universal expander button probably will expand all the way to 45 caliber so do you just pull the handle down a little at a time and eyeball how much the mouth has expanded and then use the regular resizing die? Thanks.

You adjust the universal die down a little at a time until you get the case mouth belled enough to use your normal expander ball.