I’ve been reading everything I could find regarding the use of a taper crimp vs a roll crimp for handgun ammunition with great interest because it’s an issue I have to resolve very soon.

I just bought a Dillon XL650 with every bell and whistle they make for it. I also got a set of Dillon dies for all calibers I’ll be loading. Those calibers are .38 Spl, .357 Mag, .45 ACP, 9mm, and .45 Long Colt.

Now if I am correctly interpreting “most” of what I’m reading, the majority of people loading for handguns feel that the taper crimp is best for semi-auto handgun loads such as the 9mm and the .45 ACP because it works best at keeping the bullet from being shoved back into the case on the way up the ramp. On the other hand the roll crimp is apparently best for revolver loads such as the .38 Spl, .357 Mag, and .45 Long Colt because it prevents the bullet from advancing forward in the case under recoil (like a kinetic bullet puller) and thus locking up the revolver’s cylinder. Apparently factory ammunition is loaded using a taper crimp for semi-auto ammunition and a roll crimp for revolver ammunition. At least so I am told.

So first of all, would most of you agree that a taper crimp for semi-auto handgun ammo and a roll crimp for revolver ammo seems to be the best way to go?

Secondly, I’m assuming in either case I can still use my stock Dillon carbide sizing and seating dies, but for the revolver ammo I’m going to have to purchase a different crimping die

That being the case, who makes the “best” crimping die for a rolled crimp? And is it wise to buy just the crimping die, or should I buy the whole set?

I’m told Redding, for example, makes some of the very best dies available. Could I get just a Redding crimping die for each revolver caliber – or should I buy the whole Redding set for those calibers I want to use a rolled crimp on?

I’d appreciate hearing what other hand loaders are using in their progressive presses when loading for revolver and/or semi-auto.

Thanks for sharing your thoughts and knowledge.

Secondly, I’m assuming in either case I can still use my stock Dillon carbide sizing and seating dies, but for the revolver ammo I’m going to have to purchase a different crimping die

That being the case, who makes the “best” crimping die for a rolled crimp? And is it wise to buy just the crimping die, or should I buy the whole set?

I’m told Redding, for example, makes some of the very best dies available. Could I get just a Redding crimping die for each revolver caliber – or should I buy the whole Redding set for those calibers I want to use a rolled crimp on?

I’d appreciate hearing what other hand loaders are using in their progressive presses when loading for revolver and/or semi-auto.

Thanks for sharing your thoughts and knowledge.[/quote]

You've got the taper crimp, roll crimp issue down pat. Yes, you can deviate from the "norm" if you wish but then you are on your own.

FWIW, I've been reloading handgun cartridges since 1963 (all of the ones that you've listed) and have always crimped using the crimping shoulder found in the seater die that came with my die set. For handgun ammunition, I can't think of a reason why not to use the crimp found in the seater die regardless of manufacturer. They will all work if adjusted properly. Some manufacturers offer a separate taper crimp die for the semi-auto but I have never run across a "best" crimp die be it taper or roll. My suggestion would be to save your money and use the crimp that comes with your die set. Others may disagree and provide their reasons why.

There are rifle cartridge reloaders who prefer to use the Lee factory crimp die which is a separate die. The LFC die uses a collet to provide the crimp.

Redding, among all the dies offered, has a strong following but truth be told, IMO, all of the dies will work or the manufacturers would no longer be in business.

I would say yes to your question... "So first of all, would most of you agree that a taper crimp for semi-auto handgun ammo and a roll crimp for revolver ammo seems to be the best way to go?"...

Regarding your second question..."That being the case, who makes the “best” crimping die for a rolled crimp? And is it wise to buy just the crimping die, or should I buy the whole set?"... I have used RCBS, Lyman, Redding and C-H dies for revolvers that had roll crimping capabilities in the seating dies and all worked equally well. It may be cheaper to buy the whole die set than just the seating dies. I have been able to buy excellent used dies in some gun shops for $10.00 a set. So, it depends. Take care...
Oberndorf

I don't think it's even an option. Self feeders nearly all headspace on the case, and a roll crimp will be a problem, and a straight taper on the rimmed revolver rounds will be a problem in many loads as pressures will be erratic, and low.

I've never had to crimp in a seperate step for either type of case, in 40+ years of loading ammo for both, with cast and jacketed bullets.

Thanks gentlemen. That pretty much tells me what I should do.

The only thing I'm not sure of now is how do I tell if the Dillon crimp die I have for my .45 LC is a taper crimp or a roll crimp. I know that sounds dumb, but I admit I'm new to this game. I have not really even looked at the dies yet as I'm just setting this all up.

Is it stamped on the die body (whether it's taper or roll crimp)?

It's already done for you in your die set. The seater for semi-autos are set for taper crimp whereas for revolvers it's set for roll crimp. You would have to get a separate seater die if you wanted to deviate from this arrangement and we all know you are not a deviate! Just kidding!

Redding makes a nice profile crimp die for most revolver cartridges. It is sort of a combination roll and taper crimp die. It can put a massive crimp on the ammo without bulging the case. I agree on the conventional wisdom of a roll type crimp for revolvers and taper crimp for autos for the reasons you described. But some times the autos will group better with the roll crimp if properly applied. The NRA did some serious machine rest testing with the 45ACP in one of their handloaders guides, and in some loads the roll crimp was superior accuracy wise. I guess it depends if you are serious target shooting or just plinking with the autos.

I've found another reason to apply at least a light crimp to semi auto loads and that's too assure smooth feeding. SOmetimes you just have to push the lip of the case in a bit to make the round ride smoothly up the feed ramp and into the chamber.

Hardly a "crimp"...more just taking the slight widening of the case mouth out after seating a bullet.

All factory ammo is crimped, if not problems could arise with feeding, low pressure, ect
Revolver rounds are roll crimped and auto rounds are taper crimped.
Their is no choice here. To do otherwise would cause problems with headspace.
Dillon knows this and their dies are correct. You dont need any other dies.

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THE AMERICAN HANDGUNER