40 S&W.. first time loading...Crimp?

[Bongos]

I just picked up a Dillon 550B, been loading 9mm, 45ACP, 44mag, 223 and 38 SPL. I bought the Press with accessories in a package deal, all of the above calibers included crimp dies. Anywho only the 40 S&W dies (RCBS) does not, I've set up the machine to for 40S&W and the rounds come out OK but no crimp.

Question... I know this is a snappy recoil caliber, planning on loading 180gr bullets, DO I NEED a CRIMP die? Do you guys crim;p your 40 S&W?

[Southpaw45]

I use a taper crimp on mine to apply a "very very" light crimp just to get rid of the bell. Do just like what you do with the .45ACP...

[GSwain]

Yes, i crimp my 40. I crimp fairly light, just enough so that it is visible. Not enough crimp and you will start having feed problems. I'd just wait until you can get a crimp die.

[LGB Loader]

I use a taper crimp on mine to apply a "very very" light crimp just to get rid of the bell.

yup

[XDRoX]

You already have the crimp die. It's a crimp and seating die in one. It does both. This is how all dies use to come. Dillon makes different dies to seat and crimp. Lee, Hornady, and RCBS make 3 die sets with the seating/crimping die in one.

It is a little tricky to set up, but the instructions should be pretty clear. If you want my phone number to walk you through it just PM me.

[Munk]

You already have the crimp die. It's a crimp and seating die in one. It does both. This is how all dies use to come. Dillon makes different dies to seat and crimp. Lee, Hornady, and RCBS make 3 die sets with the seating/crimping die in one.

It is a little tricky to set up, but the instructions should be pretty clear. If you want my phone number to walk you through it just PM me.

This.

The dies are: FL sizing die/decapper (step one), "Bell" die for opening case mouth (step 2) and Seat/Crimp combo die (step 3).

Many people will just back off the body of the die and dial the stem down so that it's a seat-only action when used. But if you're patient with it you can dial down the body of the die, then bring the stem down (easiest with a completed round as a reference) and use it for both in one stroke.

[Bongos]

Thanks Guys, just cancelled my crimp dies with Dillon and figured out how to set my RCBS dies to crimp.. WE ARE GOOD! (I replaced the order with primer pick up tubes... never have enough of those..)

[Munk]

Thanks Guys, just cancelled my crimp dies with Dillon and figured out how to set my RCBS dies to crimp.. WE ARE GOOD! (I replaced the order with primer pick up tubes... never have enough of those..)

Note of advice: Go easy on the crimp. If it's visibly rolled into the bullet, it's proably too much. there's so much neck tension on a .40 that just a little crimp will go a long way (mostly to make it easier to feed).

[diginit]

Use the push test and pull a couple of rounds to check that the crimp is not too deep. Cycle a mag of dummy rounds and then mic them. If the OAL is not shortened, You're good to go. Keep in mind that crimping while seating is OK, But crimping seperately after seating is better.

[sequoia_nomad]

Keep in mind that crimping while seating is OK, But crimping seperately after seating is better.

Please explain?

[sonnyt650]

roll crimp - pushing from the case head, push just the case mouth into the bullet via a shoulder in the die. For lead bullets you can go too far where the lip is too deep into the bullet to properly headspace.
taper crimp - using a camming action to lever the sides of the case into the bullet. Bullet distortion is the only result of overcrimping AFAIK.

Consider how for straight-walled semi-auto rounds the headspace is set by that lip to the head. As you make that lip less defined via roll crimping the headspace gets fuzzy. It won't get as deep as if you put it say in a 10mm chamber, however case growth is still more than with a proper lip. With people doing both chambering in 10mm and old Glocks, and me liking my 40S&W P226 and hands the way they are I'd spring for the suggested taper crimp die.

[XDRoX]

Keep in mind that crimping while seating is OK, But crimping seperately after seating is better.

Please explain?

Also very interested in an explanation. I read on this forum all the time that seating and crimping separately is better. It's just not true. People have been loading on 3 die sets for a hundred years without issue. Seating and crimping in separate stages are simply for convenience, nothing more.

It is more difficult to set up a crimp/seat die, but once it's properly set up, it works the same way.

I've also read numerous times that for roll crimping revolver rounds it's much better to do it in separate stages. Again why? If your brass are different lengths and a seating/crimp die is not crimping consistently, then why would doing it in different stages be any different?

[CalTeacher]

I seat and crimp .40 in the same stage with no issues whatsoever. I crimp just enough to where the bell is taken out of the case mouth. I chamber test a few rounds to make sure they drop freely into the chamber with no resistance, then start cranking them out.

[zfields]

Also very interested in an explanation. I read on this forum all the time that seating and crimping separately is better. It's just not true. People have been loading on 3 die sets for a hundred years without issue. Seating and crimping in separate stages are simply for convenience, nothing more.

It is more difficult to set up a crimp/seat die, but once it's properly set up, it works the same way.

I've also read numerous times that for roll crimping revolver rounds it's much better to do it in separate stages. Again why? If your brass are different lengths and a seating/crimp die is not crimping consistently, then why would doing it in different stages be any different?

When they crimp on the seat, its not a floating crimp. So with pistol brass ( which most people dont trim ) it can have a little variation.

[XDRoX]

When they crimp on the seat, its not a floating crimp. So with pistol brass ( which most people dont trim ) it can have a little variation.

Could you elaborate? I'm not sure what a floating crimp is and still don't understand why it would matter if you do it in two steps or one

Either method is going to seat the bullet and then crimp. I fail to understand why the length of the brass plays an effect in one step but not two.