Hi,

I have this set-up in .44AMP for my Lee Turret press:

- RCBS Sizing die modified to accept decapper

- Lee powder through expanding die for 44Mag

- RCBS seater

- RCBS crimp #4 CR (I'm not sure if it is the taper crimp or not? How to know?)

I would like to have a set for .357 AMP.

I was first thinking to buy a second hand RCBS set, but it might be better to get a new one from CH4D.

They're selling a 2 die set with FL sizer (I guess with decapper) + seater.

Then I should buy a Lee powder through expander for .357 Magnum.

For the crimp, what would you get?

Lee .357 MAG factory crimp, or CH4D taper crimp?

Thank you.

Don't forget that Ian has his AMT Info Site, which, among lots of other things, has that great page by Jason here on AMP dies :

http://www.amtguns.net/articles/j-waters/automag-loading-case-forming-dies/

I'm not sure exactly what your RCBS "CR.#4" die is (a standard roll crimp, or a taper crimp?), but I'd be willing to bet that Jason or others here might know. 

The RCBS taper crimp dies I've seen actually say "TAPER CR." (44 AMP) or "T.CR." (357 AMP) on them.

A couple photo examples of TC dies here, the 357 from Jason's article, the 44 from my set.

I'm thinking of ordering one of the CH4D 357 AMP taper crimp dies myself too one of these days, as I get closer to owning a 357 bbl. 

Cheers.

I use starline cases and Fiocchi SJSP bullets. Those bullets are seated very firm in the case. If not mistaken, fiocchi bullets are .430 diameter. I use the original RCBS seaterdie and almost no crimp. I never have a problem with loose bullets or bullet setback.

Also have a very good burning of the powder, meaning the bullet stays long enough in the case so the powder can ignite well.

If you can make perfect cartridges with the original RCBS dieset, why would you use an extra crimpdie?

However, if you have a problem with loose sitting bullets in the case, then I understand the reason for the extra crimp. Then I can reccomend the Factory crimpdie from Lee. Also remember that extra crimping will shorten the life of the brass.

Most of the time problems with loose bullets can be solved by changing the components. (bullets or cases)

Just my personal experience...

 

I guess the 357AMP RCBS dies will work fine. You just need your time to make the perfect setup.

I reload on a Hornady Lock-N-load ap press and use all kinds of dies in it. My 44AMP are RCBS dies and work very good. 

I see you use a 44Magnum Lee expander die, nothing wrong with those but you need to make sure the diameter of the expander plug is not to wide. You can easily turn those down to undersize. The more tension you have on the bullet the better, just give the cases some flare (slight trompet) will work fine with starline cases.

About the 357AMP, one remark about the Lee factory crimpdie: This will NOT work with the 357 Magnum die, the magnum is straightwall and the 357AMP is a bottleneck case!

I mean the die itself. You dont need to buy a new one, you can use your 44. It's easy and dont take much time to make your own expander plugs on a lathe. You can make it to the diameter you want or need.