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mehavey · July 25, 2011, 07:22 AM

As a straightwalled case which headspaces against the mouth, the 40 could best take advantage of a tapered crimp, commonly refered to (in my experience) a "factory" crimp.

By accident I discovered last week that RCBS is now supplying taper crimp seaters with their carbide 45 ACP dies and so too apparently also w/ their 40 S&W, etc. (They must have gotten the message.) So separate crimp dies may now be gilding the lily.
http://www.opticsplanet.net/rcbs-car...uto-22115.html

Conversely, light/medium recoil bottleneck cartidges (e.g., 223 Rem through 30-06 & beyond) headspace on the shoulder and can be run w/o any crimp at all using standard neck tension. If a crimp is used on those latter cartridges, a standard roll crimp on bullet having a specific crimping canelure is more than suitable.

July 25, 2011, 07:22 AM	#7
mehavey Senior Member Join Date: June 17, 2010 Location: Virginia Posts: 6,896	As a straightwalled case which headspaces against the mouth, the 40 could best take advantage of a tapered crimp, commonly refered to (in my experience) a "factory" crimp. By accident I discovered last week that RCBS is now supplying taper crimp seaters with their carbide 45 ACP dies and so too apparently also w/ their 40 S&W, etc. (They must have gotten the message.) So separate crimp dies may now be gilding the lily. http://www.opticsplanet.net/rcbs-car...uto-22115.html Conversely, light/medium recoil bottleneck cartidges (e.g., 223 Rem through 30-06 & beyond) headspace on the shoulder and can be run w/o any crimp at all using standard neck tension. If a crimp is used on those latter cartridges, a standard roll crimp on bullet having a specific crimping canelure is more than suitable. Last edited by mehavey; July 25, 2011 at 07:27 AM.