Crimping 9mm lead bullets

[Geegolly]

I have some 121g lead bullets with a groove(canalure) on the bullet. I have some basic questions. Questions I can't find answers to after searching the forums for a while.

Do I need to crimp lead bullets with a groove? Whats the purpose of filling this groove with a blue wax?

Does the bullet seating die make a taper crimp? If a crimp is required, will the crimp the bullet seating die create be sufficient, or will I need a roll crimp? What die is required for a roll crimp? Does the the LFCD make a roll crimp?

 

[NuJudge]

You have apparently obtained some cast or swaged lubricated Lead bullets. These are quite different from copper or steel jacketed bullets, in that a lubricant is necessary to prevent leaving a lot of Lead in the bore. Lead bullets also are much softer. The lubricant in swaged bullets is sometimes in a series of cannelures, but more often in one or more deep grooves cast or swaged into the bullet. After cartridge assembly, the lube and lube groove(s) is/are frequently below the cartridge case mouth

In order to facilitate bullet insertion (seating), the case mouth is flared during the assembly process. After bullet seating, the flare must be removed, and perhaps a crimp done, either by the seat die or by another die. The crimp that can be used is little more than straightening out the case, two descriptions are taper or profile crimps. Unlike revolver cartridges, 9mm cartridges headspace on the mouth of the case. If a crimp of the sort that is used on rimmed revolver cartridges ("roll crimp") was used on a "rimless" 9mm cartridge, it would probably move so far forward in the chamber that the firing pin cannot reach it.

 

[Geegolly]

Ok, so that blue stuff is actually lubricant, and that groove is just so that the lubricant can be swaged into the bullet.

I was under the impression that groove was where the crimp was supposed to be. And that was just blue wax so it would be easier to see.

 

[ninja45]

Seat the bullet past the blue lube and watch your OAL. Done correctly, you should not see any of the lube sticking outside your case/shell.

Taper crimp is generally used for for 9 mm, .40, .45, and other semi auto pistol rounds.

Roll crimp is used for revolver rounds.

 

[Cougfan2]

Taper crimp is generally used for for 9 mm, .40, .45, and other semi auto pistol rounds.

+1 9mm headspaces on the case mouth. If you roll crimp the round will likely not headspace correctly in the chamber.

 

[Werewolf]

^^^
Which makes me wonder - when building .44Magnum rounds destined to be shot out of a Magnum Research Desert Eagle - should they be taper crimped?

 

[armoredman]

Taper crimp 9mm, headspace on the case mouth.

 

[RustyFN]

Not much of a taper crimp. You only need to get rid of the bell that the expander/powder die put in. Be careful not to over crimp.
Rusty