I read the following message on another gun site: "The Lee Factory Crimp die should not be used on cases that headspace on the case mouth, like the 9mm, .45 Auto, .30 M1 Carbine, .40 S&W, etc. It does a pretty good job of mashing the case mouth into the bullet and I would guess it would affect headspace a lot. A taper crimp die is better for those kinds of things. I use the Lee die on cartridges that go into lever actions (.45-70, .450, .30-30) or other high-recoil cartridges and it works great."
What I don't understand is that people on just about every gun site on the web swear by the Lee FCD, and in those caibers (9mm & .45ACP) also. I would think they either work well or don't. Am I correct in thinking the people who say they aren't good for those calibers may be doing it wrong? There are just too many people who recommend them for them not to be any good for 9mm or .45ACP. What do you all think?

dzrtram,

There is indeed a chance of creating a dangerous situation when crimping cartridges that headspace on the case mouth. Seems that Lee accounted for that in the design of the factory crimp dies.

From:
http://www.leeprecision.com/catalog/browse.cgi?1066164980.264=dies-p3.html

"Revolver dies roll crimp with no limit as to the amount. A perfect taper crimp is applied to auto-loader rounds. The crimper cannot be misadjusted to make a case mouth too small to properly head-space. A firm crimp is essential for dependable and accurate ammunition. It will eliminate the problems of poor ignition of slow burning magnum powders."

Regards, Bill

Apparently the Lee Factory Crimp Dies for the mouth-headspacing cartridges don't produce the same sort of crimp as the others. I don't have one. I only have them for rifle and revolver cartridges that don't headspace on the mouth.

dzrtram, both Redding and Wilson make a case length gauge. If you are in doubt get one. They are generally calibre specific, and usually economical. Just drop the finished round in and check visually, no moving parts, no headaches. Either the cartridge fits correctly, or it doesn't.

It is cheap insurance!

The lee fcd for my .308 really pushes the brass into the bullet. The one I have for my .45acp does not do this it creates a nice taper crimp.

DON'T THOSE CARTRAGES ACTUALLY HEADSPACE ON THE EXTRACTOR??