Auto cartidges(ie. 9mm, 40S&W, 45acp) and the Lee Factory Crimp Die.

[GaryB]

I just started loading the 357 Sig for my son and I'm not sure about crimping. I just purchased the Lee factory crimp die
for a better crimp because of the very short neck. My question is for those people loading the auto pistol cartridges; do
you first taper crimp with the seating die then use the Lee FCD or do you just use the Lee FCD?
Probably not to many 357 Sig loaders out there so I am open to any opinions.

Thanks
GB

[Orezona]

I load for 45 ACP, Lee FCD only.

[charlie b]

The .45 carbide FCD has two parts. A carbide 'bottom' part and a 'sleeve' that provides the 'taper' crimp. When set up for my gun it only 'tapers' the last 1/4" or so.

The 9mm carbide FCD has a long taper in the bottom part, but, a similar sleeve in the top section. For my pistol the sleeve only touches the top 1/8" of the case.

Lee shows the .357Sig FCD is a collet type die like the bottleneck rifle cartridges.

The Lee seating dies can be used to apply a roll crimp. The seating dies do not apply a taper crimp.

I always use the seating die to just seat the bullet. If I want a crimp I used the FCD in a separate step.

[Orezona]

I always use the seating die to just seat the bullet. If I want a crimp I used the FCD in a separate step.

x2

[GaCop]

If you use a bullet with a crimp groove in the Sig, you can do the standard roll crimp because of the case headspacing on the shoulder. Of course, if no crimp groove you have to use the LEE FCD or collet crimp die. I didn't do a separate taper crimp before using the Lee but I don't see where that would hurt anything. For 9mm, 45 ACP, you better off using a taper crimp.

[GaryB]

Going back to my older Speer reloading manual, it says that the Sig headspaces on the case mouth and not the shoulder. I guess that's why I always
assumed that the dies(RCBS) used a taper crimp instead of the roll crimp. Also, I've always full length resized the cases.
I believe I will do both the die crimp and also use the Lee FCD for a better hold on the bullet. Like I said, not much neck to hold a bullet.
Thanks for the help.
GB

[Bill2905]

I crimp in a separate step after seating. I adjust the bullet seater so that it does not apply any crimp. I have been using the Lee FCD on 9mm, 45 ACP, 38/357, and 45 Colt for many years with good results. I switched to this die based on Lee's claim that it eliminates the risk of over crimping.

[GaryB]

Well, you have pretty well convinced me that the Lee FCD is the way to go for all of my handgun cartridges. They're fairly inexpensive and if they work as well as you say, I have nothing to lose.
Thanks guys.
Much appreciated!

[charlie b]

I would not discount the other mfgs. I know RCBS has a nice taper crimp die that can also be used to seat bullets.

[Bill2905]

Well, you have pretty well convinced me that the Lee FCD is the way to go for all of my handgun cartridges. They're fairly inexpensive and if they work as well as you say, I have nothing to lose.
Thanks guys.
Much appreciated!

I would pick one cartridge to try it on first to see if you like it. Then you can always add more if it meets your expectations.

[GaryB]

I would pick one cartridge to try it on first to see if you like it. Then you can always add more if it meets your expectations.

Yea, I bought the 357 Sig FCD so I'll give a try and see if it works out like I expect.
Maybe I'll try and talk my son into buying a different caliber pistol.

[rerun5]

Not all of the Lee FCD's do a roll crimp. Most of my equipment is Lee, and I have a FCD for all of my calibers. For the cases that headspace on the case mouth the FCD is a taper crimp die, for straight wall revolver cases it roll crimps. If you set the bullet seater for the 357 Sig to crimp you don't need to use the FCD. I have my seating die set up to seat only and I use the FCD to crimp. Get the instructions for your Lee die set out and re-read the info for the seating die and the FCD.

[GaryB]

Not all of the Lee FCD's do a roll crimp. Most of my equipment is Lee, and I have a FCD for all of my calibers. For the cases that headspace on the case mouth the FCD is a taper crimp die, for straight wall revolver cases it roll crimps. If you set the bullet seater for the 357 Sig to crimp you don't need to use the FCD. I have my seating die set up to seat only and I use the FCD to crimp. Get the instructions for your Lee die set out and re-read the info for the seating die and the FCD.

I am using the RCBS dies for the 357Sig. I did look at the instructions for those and it says they use a roll crimp.
Seems weird to use a roll crimp on a cartridge that they say headspaces on the case mouth.

[rerun5]

Lee prints the same instructions with the FCD's. If you looked at the actual die you would understand. The Lee FCD uses a collet inside the die and the collets for the semiauto pistol calibers is designed differently than the collets for a straight wall rimmed caliber. The collets in the semiauto's is machined to a taper so they will not roll the case mouth on a case that headspaces on the case mouth. I have seen this same discussion on another site and I disassembled the different dies to see, and they are definitely designed differently. Also I use the Lee FCD on all of my calibers semiauto and rimmed revolver cases, and the dies for the semiauto's doesn't roll crimp the case.

[GaryB]

Thanks for explaining the differences. Now everything makes sense.