roll or taper crimp for 38/357

[magnumb]

Hi, newbie to reloading. Just received all the goodies to start. I ordered a 4 die set from Lyman #7680200. It got good reviews especially for the expander M die which is supposed to more gently shape the case (more life) rather then just belling the end, possibly better for cast boolits.

At the time I did not notice that this set came with a seating die and a separate taper crimp die. I assumed that 38's and 357's were always roll crimped, but apparently not, as there are many taper dies for 357. For example, Redding makes both styles.

I will primarily be using cast Hi-Tek coated boooits (Missouri Bullets to start). I may load a few jacketed hollow points as well. Did I make a mistake getting this taper die in the set. #TPR CR C22. I will be using this ammo in both revolver and 357 lever action.

Appreciate the help, just getting started.

 

[dillonhelp]

A taper crimp is fine for a coated bullet. The bullet lacks a crimp groove, so applying a roll crimp will cut into the coating.

 

[mikld]

Every revolver round I have reloaded in the last 30+ years have been roll, profile or collet crimped. That's the way the bullets were designed so that's one reason I roll/profile/collet crimp. Tried taper crimping 38 Special 158 LSWC reloads in 1973(?) and had a bullet walk and lock up the cylinder. Since then I have roll, etc., crimped into the crimp groove or the cannelure...

 

[rockquarry]

I've rolled crimped and taper crimped, but prefer a taper crimp on both cartridges. With either type crimp, it's best to apply just enough to prevent bullet movement and no more. You can do some damage from an accuracy perspective with too heavy a crimp regardless of the type and many of us crimp too heavily anyway.

My results with a heavy roll crimp aiding in a better powder burn have been inconclusive.

 

[ReloadforFun]

The preference for revolvers is generally roll crimps.

Revolvers tend to pull bullets out of the case (adjacent chambers) while semi-autos tend to push bullets into the case.

Not that each crimp has been known to be used in either case.

 

[tlawler]

Roll crimping is for revolver rounds.
Taper crimping is for semi-auto rounds.

 

[TheTinMan]

Your Lyman seating die will apply a roll crimp if adjusted correctly.
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Note that these instructions assume a bullet with a cannelure when roll crimping. With coated bullets, I might try a taper crimp just this side of cutting through the coating. With regular lead bullets, I'd use a roll crimp or better yet a Redding Profile Crimp die.

I really like the Lyman M-Die expanders and use them for most pistol cartridges.

Hope that helps,
Chip

 

[diyj98]

Roll crimping is for revolver rounds.
Taper crimping is for semi-auto rounds.

That's always been my preference.

 

[38SPL HV]

I roll crimp my revolver 38/357 rounds

 

[buckshotshorty]

Roll crimp is fine for revolver cartridges because they head space on the rim. However, taper crimp is needed for most autos because the cartridge headspaces on the cartridge mouth.
If you roll crimped an auto you could cause light strikes because the cartridge will sit too low into the cylinder.

 

[rockquarry]

Roll crimp is fine for revolver cartridges because they head space on the rim. However, taper crimp is needed for most autos because the cartridge headspaces on the cartridge mouth.
If you roll crimped an auto you could cause light strikes because the cartridge will sit too low into the cylinder.

I'm not making any suggestions, but roll crimping works fine for the .45 ACP in semi-autos. Very popular some years ago and it still works well. There's a lengthy article in one of the NRA publications written by Alton Dinan in the '60s. Dinan was one of the top 1911 accuracy gunsmiths and a competitor himself. I had a Star Universal machine set up in .45 ACP and a roll crimp die was what was provided.

 

[RGPM1A]

Ever try to speed load a revolver with taper crimped rounds? It isn't pretty.

 

[LostintheOzone]

I've never had much luck shooting taper crimped ammo in a revolver, so I just roll crimp all of it, including 45 ACP. I found a 200 grn bullet for my 625 that has a groove for a roll crimp.

I'm going to try a taper crimp on my 38 Short Colt ammo because that's the only die I have to crimp that short cartridge. If it doesn't work I'll try something else.

 

[rockquarry]

Ever try to speed load a revolver with taper crimped rounds? It isn't pretty.

I'm missing something here. What's the drawback with taper crimped rounds when using a speedloader?

 

[colt_saa]

I collet Crimp every cartridge that a Lee Precision makes a collet die for

 

[Tex1001]

I collet Crimp every cartridge that a Lee Precision makes a collet die for

I use a Lee collet crimp for all bottleneck rifle and straight walled cartridges.
I've also altered Lee's crimp dies for oddball calibers
like:
357 Sig
44 Special
38 Special
32 Long
32 Auto
7.62x25
Never a problem with any of them.

 

[stansdds]

For revolver ammo, I definitely prefer a roll crimp. I tried taper crimping with some copper plated bullets as they did not have a crimping groove or cannelure. I found the taper crimp was insufficient to keep the bullets from pulling out of the cases during recoil. Taper crimp is my preference for semi-auto pistol ammon

 

[oysterer]

Like was said: If there is a cannelure: Roll crimp...if a smooth bullet: Taper. If you dont have a 357 taper, use a 9mm taper crimp die gently. Like Larry Potterfield would say: That's the way it is

 

[glenwolde]

It depends entirely on the bullet you're using. If there's a crimp groove, roll crimp. If there is not one, such as plated bullets, the taper crimp is better as it won't deform the bullet as easily.

Keep in mind that the bullet is still being seated as the crimp is applied. The case mouth will dig into a bullet and shave it a little during that moment when the bullet is almost seated but the case mouth has contacted the bullet. This is not a problem with bullets (mostly cast ones) that are of traditional design and have a for-real crimp groove. I always apply taper crimps as a separate operation from seating. Precise adjustment can make just about anything work, it's about what's likely to give you less trouble due to minor variations.

For the above reason reloaders will often apply the crimp as a separate operation. But it's really not necessary if your bullet has that crimp groove.

The old adage "roll crimp for revolvers, taper crimp for autos" is a bit of a generalization. Since the reloading tool companies all seem to make taper crimp dies for revolver cartridges it tells you they don't think that way.

There are applications for either type of crimp in either type of cartridge. With the advent of plated bullets the taper crimp is being used more now for revolver cartridges than it has been in the past.

It was fairly popular a few decades ago to use both together for heavy magnum loads to prevent bullet movement. Then Redding invented the Profile Crimp Die which is basically equivalent to adding a taper crimp to an already roll-crimped cartridge.

 

[gwpercle]

The bullet dictates what crimp to use .

Bullets with a crimp groove or cannelure get a roll crimp .
the cannelure gets a lighter roll crimp than a bullet with a deep crimp groove . These bullets are generally designed for revolver use .

Smooth sided bullets , designed for semi-auto use have NO cannelure or crimp groove , thus no place for a roll crimp to go (the case will buckle if you try too hard to roll crimp them)
So... the smooth sided bullets says Taper Crimp !

Just talk to your bullets and listen to what they say ... bullets usually speak the truth !

Post #19 is right on also ... good advice there.
Gary