Crimping 40 S&W...necessary?

[Kahyne]

Hey Calgunners,

Just like the title says. Is it necessary to crimp 40 S&W?

I was dialing in my dies, Lee 4-die Carbide set, and noticed that the crimping die doesn't even touch the bullet's case. Everything should be fine right?

Thanks in advance!

[JagerDog]

Auto pistol cases generally only need the case mouth straightened. Proper headspacing is via the case mouth. The seating dies generally have a provision for crimping though. The Lee 4 die set also includes their factory crimp die. It starightens the case mouth and in fact post sizes the case. Note with cast bullets it can swage the bullet diameter down with possible effect on ccuracy/velocity and even potential leading. Some like 'em, some don't. In part it depends if you have a sensitive gun.

Your seating die has a crimp feature built in. You can leave it set a bit high and used the FCD, or you can set it and avoid the FCD, or you can do both. The advantage of the FCD is it isn't case length dependent. Case length isn't often an issue in .40, but it can be.

[rsrocket1]

Usually, you want to simply close the flare in the case mouth. In some cases with a "barely too fat bullet", a slight taper crimp might make the difference between a good solid "plunk" and a bullet that takes a little extra effort to get totally into battery.

In this case, it helps and it is better to put in a slight crimp than to iron out the entire bulge with a FCD which as JagerDog said can swage the bullet too much.

Make sure the case is not crimped too much or it may get pinched between the throat and the bullet which would send pressures through the roof.

[J-cat]

Hey Calgunners,

Just like the title says. Is it necessary to crimp 40 S&W?

I was dialing in my dies, Lee 4-die Carbide set, and noticed that the crimping die doesn't even touch the bullet's case. Everything should be fine right?

Thanks in advance!

You have your die adjusted wrong.

[Kahyne]

You have your die adjusted wrong.

I followed the instructions on how to set it up, backed out the adjusting screw, raised the round, screwed the adjusting screw but it never touches the case mouth to a point where the adjusting screw is all the way in. Think it could be a bad die?

[the led farmer]

I followed the instructions on how to set it up, backed out the adjusting screw, raised the round, screwed the adjusting screw but it never touches the case mouth to a point where the adjusting screw is all the way in. Think it could be a bad die?

No based in what you say here your still doing it wrong. Watch this video:

http://leeprecision.net/HelpVideos/Pistol/pistol%20bs%20die-1.wmv

Done

[Kahyne]

No based in what you say here your still doing it wrong. Watch this video:

http://leeprecision.net/HelpVideos/Pistol/pistol%20bs%20die-1.wmv

Done

I have the FCD. The adjustment screw goes all the way down even with the cartridge inside. It does not stop.

[the led farmer]

I have the FCD. The adjustment screw goes all the way down even with the cartridge inside. It does not stop.

Whoops wrong video sorry-

http://leeprecision.net/HelpVideos/Pistol/carbide%20fc%20die-1.wmv

If you are doing like it shows and your still not having luck your die is defective.

[Kahyne]

If you are doing like it shows and your still not having luck your die is defective.

That's not what I wanted to hear. LOL!

[the led farmer]

That's not what I wanted to hear. LOL!

Bummer. Send it back to lee precision they'll send you a new one lickity split

[J-cat]

I followed the instructions on how to set it up, backed out the adjusting screw, raised the round, screwed the adjusting screw but it never touches the case mouth to a point where the adjusting screw is all the way in. Think it could be a bad die?

Did u check if the die is complete with a crimping sleeve inside that the screw can push on?

[Paperchasin]

I just started loading .40 S&W as well and currently using an RCBS 3-die carbide set. Picked up a separate 4th die for crimping only. I ran a couple of batches of 50-rds, with and without crimp, and found that they all fed reliably in my firearms.

[stand125]

I pulled a factory 40 cal bullet one time to see how much crimp was present and was really surprised at how much crimp that factory bullet had. The Bullet had a definate crimp line around the FMJ bullet. I crimp my 40 cal ammo to where I can just make out a crimp line around the bullet when pulled.

[stand125]

I followed the instructions on how to set it up, backed out the adjusting screw, raised the round, screwed the adjusting screw but it never touches the case mouth to a point where the adjusting screw is all the way in. Think it could be a bad die?

I know this is going to sound like a dumb question, but did you screw the crimp die itsself down untill it stopped against the shellplate and then screwed in the crimp adjusting knob untill it stopped which would have been the top of the case mouth.

[Kahyne]

I know this is going to sound like a dumb question, but did you screw the crimp die itsself down untill it stopped against the shellplate and then screwed in the crimp adjusting knob untill it stopped which would have been the top of the case mouth.

Yup did that. I emailed Lee Precision and it looks like there was a bad batch of crimping sleeves then went out with the Carbide 4-die sets. Here is their email:

"Nate:

There was a batch of 40 S&W Factory Crimp Dies that got out with the wrong Crimp Sleeve in them and it sounds like you received one. We will send the correct Sleeve out to you right away.


Thank You,

Laine
Customer Service"

Thanks for everyone suggestions and help. Same time I received this email, I had a shipping confirmation for the correct sleeve on its way.