38/357 Roll crimp vs taper crimp ?

[BruniX]

Hello everyone,

at the end of the year, I will start reloading for the 38 special and the 357 magnum.
I will finally get the pink paper of the shooting club that allows here to ask the authorities the authorization of buying and holding a handgun.
(I would like a ruger gp 100 or S & W 586 )
looking at the RCBS die, I saw that there were two kinds :

- 38 Special / 357 Mag Carbide Roll Crimp Die 3 - RCBS 1812
- 38 Special / 357 Mag Carbide Taper Crimp 3 Die Set - RCBS 1815

Can anyone explain to me the difference between roll crimp and type crimp?
Is there any advantage in taking one over the other?

[Mistered]

Can anyone explain to me the difference between roll crimp and type crimp?

Roll crimping is simply the mouth of the case is given a slight 'roll' into the cannelure of the bullet by the seating die during the bullet seating operation.

A taper crimp is where the mouth if the case is 'squeezed' around the bullet in a slight taper yet leaves the rim square.
Taper crimping is normally used for semi auto ammo due to the round headspacing on the rim of the cartridge.

You might want to consider a collet style crimp die and there is a lot of info posted about them.
While it makes crimping a separate step the advantage with the collet style crimp die is the crimp is unaffected by slight differences in case length as MOST reloaders of straight wall cartridges do NOT trim their cases. Because the typical roll crimp process makes contact with the rim of the case one round might have a satisfactory crimp while the next might have too heavy of a crimp if the case is slightly longer.

[BruniX]

Can anyone explain to me the difference between roll crimp and type crimp?

Roll crimping is simply the mouth of the case is given a slight 'roll' into the cannelure of the bullet by the seating die during the bullet seating operation.

A taper crimp is where the mouth if the case is 'squeezed' around the bullet in a slight taper yet leaves the rim square.
Taper crimping is normally used for semi auto ammo due to the round headspacing on the rim of the cartridge.

You might want to consider a collet style crimp die and there is a lot of info posted about them.
While it makes crimping a separate step the advantage with the collet style crimp die is the crimp is unaffected by slight differences in case length as MOST reloaders of straight wall cartridges do NOT trim their cases. Because the typical roll crimp process makes contact with the rim of the case one round might have a satisfactory crimp while the next might have too heavy of a crimp if the case is slightly longer.

Very interesting !
RCBS sell a distinct collet crimp ?
with 45-70 i use a lee factory crimp tool...

About too heavy crimp, is it dangerous to use ammo with too heavy crimp ?
explosion is possible ?
(i am afraid of doing too much this step ... )

[Mistered]

RCBS sell a distinct collet crimp ?

I don't know if RCBS makes them. Lee seems to have the market cornered on them and are called the 'Factory Crimp Die'

About too heavy crimp, is it dangerous to use ammo with too heavy crimp ?

Chances are by the time you crimped a round too heavily you would have bulged it to the point it would not chamber.
Read your reloading manual about loading pistol ammo and it will explain crimping in detail.

[JEBar]

concern understood .... its my understanding that the major concern with overly heavy crimps is its flexing shortens the live of the brass ....

[Mistered]

The upside to a collet crimp die is you cannot 'overcrimp' a round as the collet can only close down so far and stops when the separations meet.

img20190926_14143922.jpg (245.79 KiB) Viewed 3378 times

img20190926_14295160.jpg (230.14 KiB) Viewed 3378 times

[Ojaileveraction]

I've been fretting about FC and taper crimp dies.
I found this on the Midway sight looking at a Lee taper crimp die.

Lee products
The Lee Taper Crimp Die is hardened steel designed to overcome crimp problems caused by poor die design. These dies offer little or no advantage when used with 1986 or newer Lee dies as the crimp angle is already a modified taper crimp. Jacketed bullets must have a crimp groove (cannelure). Shellholder sold separately. Comes shipped with a plastic storage case.

[BigAl52]

I feel like crimp dies are a personal preference. Ive used several different ones and havent really seen enough difference accuracy wise to say one is better than the other.

[krunchnik]

The real intent of the crimp is to keep the bullet from jumping forward during recoil and tying up the revolver-accuracy is only a secondary need.
All of my .357-.41 mag are ran thru a Lee Factory Crimp die

[clovishound]

RCBS sell a distinct collet crimp ?

I don't know if RCBS makes them. Lee seems to have the market cornered on them and are called the 'Factory Crimp Die'

The normal Lee Factory Crimp die applies a roll crimp. Lee does make a collet style crimp die for .357, but it is called a collet style crimp die.
https://leeprecision.com/357-magnum-cus ... p-die.html

For most applications, the normal seat/crimp die works just fine for .357. The taper crimp in this caliber is sometimes recommended for plated bullets that lack a canelure. I always buy .38/.357 bullets with a canelure. Most do. If you prefer to have the case sized after seating, then get the factory crimp die. It will do this, although it does require an additional pull of the reloading handle, if you are not using a progressive. I have seen no advantage to using a Lee FCD in pistol cartridges. I have used both the FCD and the standard seat/crimp dies in both .357 and 9mm. I now use the standard seat/crimp in both.

[Ojaileveraction]

I have found out that the Lee Carbide Factory Crimp Die will resize all lead bullets to a common size. (Don't remember what)
So if you use a larger bullet due to an oversized barrel it will resize that bullet smaller.

But if you that advanced in your reloading I'd think you would figure that out pretty fast.

[Rifletom]

I use the Lee FCD on .357/38 spl, .45 acp, .45 Colt and 30-30 Win. These are super easy to use and "cheap insurance". I have never had an issue with them. One extra step is no big deal in my case. They just make my handloading much easier. Works like a charm.