Home Forums Reloading Big Game Rifles Pistol case cannelures

Hi guys, can you lighten me up a little here? I have reloaded for rifles for some time but now I am thinking about starting loading for pistols. I see that on most pistol cartridges there are tvo crimps. I saw also on a drawing that one is so called bullet cannelure but the other case cannelure. What is this second cannelure for, how does it come into the picture in the reloading process and how does it come into die adjustment and so forth?

Thanks and best regards,
Kakali

For all practical purposes, you can ignore the case cannelure. The case cannelure is created with a special tool such as Corbin's HCT-1. If the bullets in your handloads are "setting back" in spite of a healthy crimp on the case mouth, a cannelure crimp might solve the problem.

If your loads actually needed a cannelure crimp, you'd be the first guy I know. I think most folks that use them do so for authenticity and because case cannelures are cool looking <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />.

The key to handgun crimps is using the right type. Die sets sometimes come only with a "roll crimp" die, which is not suitable for cartridges that headspace on the case mouth (semi-auto's). Cannelured bullets shouldn't be used in this case anyway. The roll crimp is generally used on revolver cartridges that headspace on the rim.

A "taper crimp" is used on cartridges that headspace on the case mouth.

With many case filling, bulky loads there is really no practical reason for them nowdays with the strong case mouth crimp commonly in used on any heavy recoiling load. The case mouth crimp should prevent movement of the bullet either in or out of the case while the case cannelure would only prevent the bullet from being driven deeper into the case, a problem which would likely only show itself if the cartridges were being used in the tube magazine of a rifle or if cartridges with small charges were handled roughly. Recoil will normally "pull" bullets from the case rather than drive them deeper.

I imagine there may be one thing the case cannelure was originally intended for and that is the safety of pistol loads. As many know, seating depth can really affect pressures with the "quick" powders often used in pistol cartridges. Bullets that are seated in too far for whatever reason can cause pressures to skyrocket. The case cannelure can prevent that, especially in mass produced and otherwise uncrimped ammo. Ammo which doesn't produce a lot of recoil often doesn't need a case mouth crimp. The case cannelure does have a real function then.

As a sidenote, I was concerned when some 45 Colt brass I bought for only bullet crimped loads showed up with the case cannelure. I thought it might weaken the cases at that point. It turns out that those cases have lasted through many heavy loads over several years and none has failed at the cannelure.