# Taper crimp or roll crimp for 9mm?



## Huge29 (Sep 17, 2007)

I have been loading for rifle bullets and now looking to expand to pistol loads. I see the 9mm dies come in taper or roll crimp. I have snooped around here and there and I can't say that I understand it any better than before. Any help and recommendations would be appreciated.


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## DallanC (Jan 13, 2009)

Do not roll crimp, 9mm headspaces off the case mouth. Taper is all you need.


-DallanC


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## Huge29 (Sep 17, 2007)

i was starting to arrive at that conclusion from other readings, but why would they even offer the roll? Is there another use for a 9mm other than an autoloader? Just wanting to understand.


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## Mavis13 (Oct 29, 2007)

Ya got me; you roll crimp cases that head space on the rim such as revolver cases like .357, .41, .44, mag; taper is the only one that will work in a 9mm. I've been using the 4 die set from Lee; though the 4th die seems redundant as the seating die crimps it; the 4th one supposedly puts a better taper on it so it will load better. I've loaded with it and without it and can't find any difference but 4 is better than 3 so I use it.


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## sagebrush (Sep 8, 2007)

your seating is the one that will provide the roll crimp. the only way to get a taper crimp is with a taper crimp die, that is why you have 4 dies with the lee set.

a roll crimp is also used to prevent bullet set back when a tubular magazine is used as such in the lever action rifle.

huge29 use a taper crimp on a semi-auto pistol


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## DallanC (Jan 13, 2009)

Mavis13 said:


> I've been using the 4 die set from Lee; though the 4th die seems redundant as the seating die crimps it; the 4th one supposedly puts a better taper on it so it will load better. I've loaded with it and without it and can't find any difference but 4 is better than 3 so I use it.


The 4th die is nicknamed a "goof" die. It fixes problems if you have mis-adjusted the previous dies and bulge your case or something. If you properly set up your dies in the first place, you wont need the 4th. Other mfgs like RCBS dont make that die, you just get the first 3.

-DallanC


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## Gee LeDouche (Sep 21, 2007)

Semiauto = taper
Revolver = Roll


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## lifes short (Sep 11, 2013)

The roll crimp can be used as long as it is adjusted properly. You just want to bring your flare back in and crimp slightly. If you adjust it too deep it will not headspace properly. If you are using cast bullets you can adjust the taper crimp improperly also. Too much taper crimp swages down your bullets. Either one must be adjusted properly.


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## El Matador (Dec 21, 2007)

^^^^What he said^^^^

Most bullets you would shoot in a semi auto don't have a cannelure or crimp groove anyway. I adjust the crimp so that it just snugs the brass against the bullet. The Lyman M expander is a pretty sweet die to have since the expander profile has 2 steps. This allows you to keep the flare to a minimum and still have the bullet align well as you seat.


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