Need help with taper crimp setup

Pilotscrappy

Winter is coming
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Minuteman
Jul 21, 2018
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Spring Hill,Tn
Hey guys I'm trying to get my rcbs taper crimp dies setup properly and have been struggling. I have never loaded pistol on my own before so this is a learning time for myself.
I'm following the instructions on the paperwork with the dies on getting the taper crimp setup properly for the 380 cartridge I'm loading. I thought I had it dialed in then the first two rounds I made came.out like this in the pics.

So my question is this. According to the rcbs instructions, I should have a measurable crimp (from calipers) by like 1 to 2 thousands difference from the case mouth to the bottom of where the bullet sits in the case . I can't seem to get that measurement without crimping to much? Can I just crimp enough and eyeball it to make sure the flar is gone from the case mouth?
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I like to use Lee factory crimp dies. Seat the bullet then go through and crimp them all. I have done the seat and crimp. Make sure you read and under stand the instruction for the seat and crimp. I always gauge my crimp by how far down past touching the case I go 1/4 turn 1/2 turn full turn. cases also need to be same length. maybe its the pics but I don't see much of a crimp on any of them. You got the right seating plug in there?
 
Taper crimp should be just enough to remove that flare. The rounds in your first pics show the case buckling. Your seating depth and crimp position in the die aren’t aligned and causing the buckling. What I would do is remove the seating stem and adjust the die so the case is just barely entering the crimp groove in the die. Lock the die collar and then put a 7/8 washer underneath the die to shim it above the crimp groove. Now set your seating depth with the seating stem. You should have an un-crimped round with the desired bullet seat depth. Now back off the seating stem and remove the 7/8 washer. Run the cartridge back into the die to crimp the case mouth, and screw the seating stem back in until it makes contact with the bullet. Now your die is adjusted for both.

Personally I don’t use taper or roll crimps on semi auto cartridges, a lee fcd seems to work better for that application. I only roll crimp .357/38 and .44spcl/mag bullets with cannelures or crimp grooves.
 
The rounds in your first two pics look *way* over crimped. That can cause overpressure/safety issues. I’ve found that less is more when it comes to taper crimping pistol rounds, especially if it’s just for plinking/target ammo.

That said, I use carbide Rcbs dies but I’m considering buying a Lee factory crimp die so I don’t have to concern myself with it.
 
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I have a 12 year old post-it note at my reloading bench that says NO MORE ROLL CRIMPS. All my pistol die sets have lee fcd’s in them. Even had one for 5.56 plinking ammo. The other thing to consider, with semi auto pistols, the cartridges headspace on the case mouth. If you taper crimp too heavily it will affect the cartridge’s ability to headspace correctly in the chamber.
 
maybe its the pics but I don't see much of a crimp on any of them. You got the right seating plug in there?
I was afraid of that ,to be totally honest I'm not exactly sure what I'm looking for I've never loaded pistol and my rifle stuff I've never crimped.

When I was adjusting the seating plug, according to then instructions from rcbs it said to seat the bullet to the correct oal before I start messing with the crimp. I ran out of adjustment before I could achieve the oal I was trying to get (.980)
So I screwed the die down a couple of turns then backed the plug off a little bit and then was able to get the correct oal.

Rcbs only provided the one seater plug with this 3 die set. Is it possible I need a different seater plug ?
 
Yeah, your first picture had waaaaaay too much crimp. It should be just a kiss, like .002 or .003". Plus with your plated bullets, a case with too much crimp into the plating can cause separation of the plating from the lead slug.
Oh yeah I figured those first two were toast I chucked them in the garbage already.

I'll have to keep playing with it cuz now I don't think I'm getting any crimp at all. I can't visibly see anything on the case mouth indicating a crimp
 
The reply above suggesting that you should adjust the die to just push the lip of the case in to flush to the side of the bullet is correct. If you try to crimp beyond that it will buckle the cases as you did. 1) Set the die and lock ring so that no crimp is attempted. 2) Gradually seat a bullet to the desired overall length just using the seating stem adjustment without trying to crimp. 3) Back out the seating stem, loosen the die body lock ring and hand tighten the die down until you feel it contact the lip of the case rim. 4) Back the case out of the die and turn the die body down/in about 1/16th turn and tighten the jam/lock nut. 5) Be sure the seating stem is backed out far enough to not contact the bullet. 6) Run the loaded case up into the die till it stops. 7) Remove the loaded and inspect for the case mouth flush to the side of the bullet. If it isn't enough repeat steps 4 through 7 until the desired results are achieved. Don't try to crimp it. Only bullets with a canilure groove are designed for a crimp. 8) Once you've achieved the desired results, make sure the jam/lock nuts are all secured. You can now use the die to seat the bullet and squeeze the case mouth flush to the case in a single operation. Remember, the cases must all be a uniform length for this to work.
 
The reply above suggesting that you should adjust the die to just push the lip of the case in to flush to the side of the bullet is correct. If you try to crimp beyond that it will buckle the cases as you did. 1) Set the die and lock ring so that no crimp is attempted. 2) Gradually seat a bullet to the desired overall length just using the seating stem adjustment without trying to crimp. 3) Back out the seating stem, loosen the die body lock ring and hand tighten the die down until you feel it contact the lip of the case rim. 4) Back the case out of the die and turn the die body down/in about 1/16th turn and tighten the jam/lock nut. 5) Be sure the seating stem is backed out far enough to not contact the bullet. 6) Run the loaded case up into the die till it stops. 7) Remove the loaded and inspect for the case mouth flush to the side of the bullet. If it isn't enough repeat steps 4 through 7 until the desired results are achieved. Don't try to crimp it. Only bullets with a canilure groove are designed for a crimp. 8) Once you've achieved the desired results, make sure the jam/lock nuts are all secured. You can now use the die to seat the bullet and squeeze the case mouth flush to the case in a single operation. Remember, the cases must all be a uniform length for this to work.
Thank you will give this a go
 
Try it as listed above. Sometimes they give you 2 seater plugs one for flat nose one for round nose easy to tell the difference by looking. My only RCBS pistol die set is .357 though which was my first. After that went to Lee dies. I really like the factory crimp dies. If you still have trouble you could always back the die out so it is NOT crimping run through and seat all your bullets. Then back out the seater and set the die body to crimp and run through them all you will have a better feel for the crimp.
 
This is why using the 7/8 flat washer as a shim is great. Once the die is adjusted for your taper crimp you won’t have to adjust the die body again. Simply screw the die into your press on top of the washer and adjust your seating depth. Much easier than re-adjusting the whole die every time you switch bullets. I don’t seat and crimp in one step anymore, the lee fcd just does a better job crimping and has a sizing ring to iron out any bulges your case may have left over from the seating step.
 
Yeah, your first picture had waaaaaay too much crimp. It should be just a kiss, like .002 or .003". Plus with your plated bullets, a case with too much crimp into the plating can cause separation of the plating from the lead slug.
2 guys nailed it here, heed this advice, only with jacketed bullets should one seat and crimp in the same motion. Lead and plated bullets can roll if too aggressive.
 
Oh yeah I figured those first two were toast I chucked them in the garbage already.

I'll have to keep playing with it cuz now I don't think I'm getting any crimp at all. I can't visibly see anything on the case mouth indicating a crimp
Calipers are your friend. Lee Factory Crimp Die is the answer.. roll crimping is for revolvers, or other cartridges where the headspace isn't from the case mouth.

Measure the case mouth before crimping, them measure after crimping. According to the SAAMI blueprint, a .380 cartridge has a case mouth diameter of 0.374". If you crimp 2-3 thou, well your case mouth will be 0.371-0.372"

This is 9mm, but it has the same case mouth diameter as 380.
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Several people have provided excellent/correct advice, but I will pile on. When I first started loading for pistol (.357 Mag/50 AE) I thought that "crimping" was supposed to jam the cartridge case into the bullet. Nope. You are only crimping to remove the bell you put in the case so that you could seat the bullet. Once you have the proper seating depth and you back that off and screw down the die until it hits the case mouth, you should only need to go about another 1/16 turn on the die. One-Sixteenth turn. That should remove the bell and give you the proper crimp.

Edit: I’ve been using Hornady seating/taper crimp dies for .357 Magnum, .50AE and .45 Colt, no problem. The trick is to resist at all cost the overwhelming urge to “over crimp”.
 
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the taper crimp die is also the bullet seating die.

This is the issue IMO...

I know a lot of people use these with good results, but more people get results like yours.

I ONLY seat and crimp in 2 steps.

And the Lee FCD is the way to go for crimp dies unless your die set comes with separate seating and crimp dies like the Dillon die sets do.