RCBS 357 Mag Dies for 38 Special

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bamboo633

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I have recently been gifted some RCBS dies marked "Group B, Part #18206, 3 Die Set 357 Mag SWC". I also received a separate die marked "Group B, Part #18341, Seater .38 Spec WC". They date to 1979 according to the stamps on the dies themselves. What can I say, the price was right...

My question is, can I use the 357 Mag dies to size, deprime, and flare the case mouth for bullet insertion on 38 Special brass, then use the 38 Special die to seat bullets or are the 357 dies specific to that caliber?

Also, can the 357 seating die be used on semi-wad cutters only or can I seat wad cutters as well? The same goes for the 38 die, WC only or can they be used for SWC seating?

As you have probably surmised, I am fairly new to reloading handgun rounds. I understand the basics and have reloaded rifle rounds but I am getting into handgun after a recent S&W 586 purchase.
 
I have used a couple different sets of .38 / .357 dies interchangeably with both. The only difference between the two cartridge cases is length, and they are straight sided, so it only depends on how far you slide them into the die. Try the .38 WC seater with your .357 Wad cutters, it should work fine. Just adjust the crimp according to the case being used, by varying how far you screw the die into the press.
The SWC seater used for full flat nosed WC profile might roll the edges too much inward, you could try one or two to find out but it's usually best to stick with the recommended seater stem profile.
 
You are good to go. I have two die sets in 357 magnum. One stays in my turret press, one get adjusted for 357 magnum and 357 maximum. All that is required is to adjust your die in or out and my seating plugs get changed according to nose profile.
 
As I recall..The Rcbs 357/38 special dies came with a spacer ring that would accommodate the difference in case length. Set the dies for 38 and when loading 357 insert the spacer ring to elevate the die.
 
Sounds like I should be good to go. I will try a few first and see what happens.

I was just curious because this is not marked 38/357 like every other set of dies I have seen, it is just marked 357.

I will stick to the recommended nose profile for now.

Thanks all.
 
257Wby said:
As I recall..The Rcbs 357/38 special dies came with a spacer ring that would accommodate the difference in case length. Set the dies for 38 and when loading 357 insert the spacer ring to elevate the die.
Click to expand...

I can confirm this... my 44 Mag / special dies came with spacer ring which is really just like a large washer.
 
Older RCBS dies would use the decapper pin and neck expander in the same die. Therefore if the dies were .38 Special, they wouldn't work for .357 Magnum.
 
I have verified these to be the older style with the decapper and neck expander in the same die. I think I am just going to have to give them a try. Any problems should be easy to see.

Thanks.
 
My RCBS dies are older with a steel resizer. I use a lee resizer. The expander and decapper together is no problem as long as you use a decap pin long enough to push the primer. I replaced mine. A good idea is to have extra decapper pins for every type of die you own.
 
bamboo633 said:
Sounds like I should be good to go. I will try a few first and see what happens.

I was just curious because this is not marked 38/357 like every other set of dies I have seen, it is just marked 357.

I will stick to the recommended nose profile for now.

Thanks all.
Click to expand...

When you adjust your case mouth expander, only expand the cases just enough to accept the heel of the bullet (the outside edge of the base) and your brass will last much longer. Cast bullets might require a bit more expansion than jacketed, since they are softer and larger diameter than jacketed. If you don't expand your case mouths at all, you'll shave lead off cast bullets, and crumple cases when seating jacketed bullets. If you develop a habit of seating the bullet and crimping in two separate steps, your round to round uniformity will improve. It will be less frustrating if you chamber each handloaded round into your revolver before heading to the range, that way you know all of your rounds will chamber. If every now and then a handload doesn't chamber easily, purchase a Lee Factory crimp die, not only does this uniform the crimp, it also resizes the loaded cartridge which ensures effortless chambering.
 
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