Newb question on taper crimp for cast bullets


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Dewey 68
June 2, 2010, 12:29 PM
Got a newb question for all of the reloading vets out there. I'm getting ready to reload 9mm rounds with some MBC 115 grain LRN bullets. I haven't picked up primers and powder yet, but I've been playing with the press (Lee Pro 1000) and dies to familiarize myself with how everything works before I start reloading live rounds.

My original experiments with seating and crimping the bullets seemed to be putting on a bit too much of a taper crimp. When I would use an inertia puller to pull the bullet, there would be a small indentation ring around the base of the bullet above the lube channel. Maybe 1/32'nd of a inch. It would take 3 good whacks on the bench to get the bullet out.

Since then I backed the die out, and moved the seating plunger in a bit, and now it only takes one whack to pull the bullet, and I have a small line maybe halfway around the bullet, not even a full ring.

My question is, with cast bullets, is it ok to have a little indentation on the bullet after crimping, or should there be basically no visible signs of the crimp after pulling a bullet?

I don't want excess pressure, but I don't want the bullets getting loose while in the magazine either.

Thanks for any help!

BTW, I've got the Speer and Lyman manuals, and the ABC's of Reloading, but I can't really find anything that addresses this question.

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DIV03
June 2, 2010, 06:33 PM
I do not own any Lee reloading equipment. However the taper crimp is used to remove the bell from the case mouth after the bullet has been seated. You want to just remove the bell and not crush the case mouth into the lead bullet.

Walkalong
June 2, 2010, 06:52 PM
Yep. Taper crimp to remove the bell and perhaps a hair more. It is not to hold the bullet. Neck tension is for holding the bullet in an auto case. No amount of crimp can make up for poor neck tension.

If you do not have adequate neck tension either the sizer is too big, or the expander is too big

You could try polishing down your expander die if you do not have enough neck tension if it seems to be doing to much.

Welcome to THR

243winxb
June 2, 2010, 07:27 PM
My question is, with cast bullets, is it ok to have a little indentation on the bullet after crimping, or should there be basically no visible signs of the crimp after pulling a bullet? A small amount should not hurt. The 9mm headspaces on the case mouth, so you do not want a lot of crimp. Are you using Lee dies also? If so, you need to know that Lee seating dies taper crimp then turn into a roll crimp. If the die is screwed in to far, you over crimp. Seating die crimp style

There are two crimp shoulders in our bullet seating dies. The first shoulder applies a slight taper crimp and the second shoulder applies a full roll crimp. The closer the die is adjusted to the shell holder the heavier the crimp will be.
9mm gets a taper crimp :scrutiny:

Dewey 68
June 2, 2010, 07:27 PM
Thanks, it sounds like I have it set about right then. The cartridges are feeding fine in my gun.

Now I just need to make a run to Bass Pro and get some primers and powders. The other places around me are still charging obscene amounts for reloading consumables.:what:

A lot of good information here, I've enjoyed reading your posts with the great pictures of roll crimps, Walkalong. My next goal is to get a gun that requires cartridges with roll crimps. :D

Walkalong
June 2, 2010, 09:06 PM
next goal is to get a gun that requires cartridges with roll crimps
Heck, that's easy. ;)

Pics when ya do. :)

greyling22
June 2, 2010, 10:03 PM
the lee bullet seating die will do a roll crimp. great if you don't have a factory crimp die, but not so good if you do. unscrew the bullet seating die until you no longer get a roll crimp, adjust bullet seat as needed for proper depth, then use the factory crimp die for a light crimp. unless lee's changes something in the past few years.

Dewey 68
June 2, 2010, 10:26 PM
Lee Pro 1000 is only a 3 stage press, so no FCD.

In the spirit of all of Walkalong's great pictures, here is one of two pulled bullets. The one on the left is with my original die adjustment, the one on the right is what I think is a better taper crimp. You can just make out the slight line.

243winxb
June 3, 2010, 08:09 AM
Dewey 68, your photo is a perfect example of the reason NOT to use Lee dies. When you buy a die set for a 9 40 or 45, the die set should only taper crimp, and thats it. Not turn into a roll crimp :uhoh: :D IMO :neener:

Walkalong
June 3, 2010, 09:17 AM
The one on the right looks good. If you don't think you have sufficient neck tension, polish the expander down some. I have a couple of calibers where no expansion is going on, just a bit of belling, and no more belling than needed to seat the bullet without lead shaving.

I really need a tighter .38 sizer. I am borderline on neck tension. I had one that was good, but the carbide ring popped out. I "fixed" it myself, but I obviously did not do a good job, because it came out again. I either need to fix it better this time, or get another one. The one I am using is "OK", but it doesn't give the neck tension I want. Maybe I'll get off my duff this weekend and fix it.

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