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Old 09-02-2012, 15:25   #114
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Originally Posted by pasky2112 View Post
No! The die is doing a lot of stuff including trying to swage the bullet diameter. There is absolutely no love for that die by the majority of people on this forum. It attempts to solve a problem that doesn't exist and creates some new ones while doing it. You just don't need it.

A taper crimp die is the proper way to get the flare out of the case mouth.

So, How else would one objectively measure an over crimped rnd? Why would I NOT crimp?? as someone suggested? The only rnds I don't crimp are my single-fire rifle rnds.
You want to straighten out the flare without swaging the bullet diameter. You don't want the case mouth to indent the bullet in any way.

You should crimp bullets that have a cannelure - particularly heavy recoil cartridges like .357 mag or .44 mag. You shouldn't crimp cartridges that headspace on the case mouth like .380, 9mm, .40 S&W, 10mm, .45 ACP. AFAIK, the story is the same for .357 SIG because SAAMI says the cartridge headspaces on the case mouth. I believe it really headspaces on the shoulder like every other bottle neck cartridge. In any event, no noticeable crimp. Just straighten out the case mouth.

You can use a lot of different dies to attempt a taper crimp. However, the taper crimp die is actually intended to slowly taper the case mouth and is much easier to get set up properly. Most other dies want to make a roll crimp and might be coerced into closing the case mouth but it will be highly dependent on case length.

There's just no reason to use the wrong die. Taper crimp dies don't cost all that much.

"No matter how cynical you become, it's never enough to keep up." - Lily Tomlin

Last edited by F106 Fan; 09-02-2012 at 16:14..
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