Roll Crimp or Taper Crimp for 38/357?

[Shrinkmd]

Another newbie question, which I didn't find a simple answer to, so here it goes...

I see that the Hornady die set comes with a roll crimp in 38/357, but RCBS sells a roll crimp and a taper crimp set.

What are the pros and cons of roll vs taper? Is one meant more for lead/plated and the other for jacketed bullets? From what I've read so far, it looks like a taper crimp might help feeding in a Marlin carbine, and might help with bullets not moving due to recoil (well, from a different cartridge being fired, that is ) Did I read correctly, however, that taper crimping can lead to reduced brass life? Is this a real life issue or just theoretical

Kind of like the religious arguments about using liquid brass polish with the media in the tumbler reducing brass life, vs people reporting they have been doing this for decades, or 9 vs 45, or revolver vs auto, or cleaning a 22lr barrel vs not...

So for my purposes, I intend to both shoot up a lot of nice light to medium target loads with hard cast or plated like Oregon trail or Berrys in 38 or 357 (BTW, if you are using lead, is there any advantage using a 357 case vs 38? Aren't they loaded the same, given they are the same bullet, same max FPS to avoid leading and work properly?) But I would also like to brew up some nice jacketed FMH or JHP and have some 357 magnum fun.

 

[Uncle Chan]

I shoot revolvers and lever actions. Roll crimping is pretty much required. My Lee Factory Crimp dies does a perfect job. I wouldn't use anything else.

 

[dagger dog]

I thought a taper crimp was used to "headspace" on the case mouth.
Does any one know of any other .357 mag auto loader other than the Koonan?

That would be the normal use of a taper crimp die , for auto pistol that headspaces on the case mouth.

Revolvers use roll crimp.

 

[Walkalong]

38/357 Crimp

For lead bullets with a crimp groove, I roll crimp into the crimp groove.

With plated bullets, I taper crimp.

With jacketed bullets with a good cannelure, I sometimes roll crimp and sometimes taper crimp. Generally, if it is a light target load I'll taper crimp, but if it is a heavy load, I'll roll crimp, depending on the powder.

The Redding stand alone taper crimp die will produce anywhere from a nice light taper crimp on a plated bullet to a nice heavy taper crimp on jacketed bullets.

That would be the normal use of a taper crimp die , for auto pistol that headspaces on the case mouth.

Revolvers use roll crimp.

Yep

 

[Ben Shepherd]

So for my purposes, I intend to both shoot up a lot of nice light to medium target loads with hard cast or plated like Oregon trail or Berrys in 38 or 357 (BTW, if you are using lead, is there any advantage using a 357 case vs 38? Aren't they loaded the same, given they are the same bullet, same max FPS to avoid leading and work properly?) But I would also like to brew up some nice jacketed FMH or JHP and have some 357 magnum fun.

Those Oregon Trail bullets are hard cast. Much different animal than soft swadged lead. I've run them as fast as 1600 without leading.

For your mid range plinkers with plated bullets the taper crimp may be the cats meow. You won't tear the plating, and the brass should last a LONG time.

With the lead slugs with a crimp groove, run the roll crimp. And with the specific cast slugs you mentioned, you should be able to run clear to the top of magnum velocities without issues. Just remember each individual gun is a law unto itself.

 

[rcmodel]

RCBS sells a taper crimp die in revolver calibers for use in semi-autos like the Auto-Mag, and in single-shots like the Contender.

Revolvers normally require a roll crimp to prevent recoil from pulling the bullets.

SOP is:
Revolvers & Lever-actions = Roll Crimp.
Auto's, & S/S's = Taper Crimp.

rc

 

[Shrinkmd]

And with the specific slugs you mentioned, you should be able to run clear to the top of magnum velocities without issues.

Wow, so for 100 bucks per thousand for the hard cast bullets, 30 bucks for primers, and then some powder (obviously the prices go down when buying in bulk, but hey I'm just starting out) I can shoot full house 357 magnum cheaper than buying 9mm wolf?

I think I'm going to really like reloading, and like everyone says, I won't save a dime in the end. But if I can shoot 357 till the top strap is burned away and needs a new frame, that could be fun...

 

[jfh]

"...I can shoot full house 357 magnum cheaper than buying 9mm wolf?"
​

I dunno what the cost of Wolf 9mm is--but I can tell you that I consider my reloading costs for full house .357 rounds to be about 12-13 cents per round, or the equivalent of $6.50 per box of 50.

That includes an amortized cost for new cases--which, with full-house rounds, I consider depleted after about five uses.

Jim H.

 

[Steve C]

For lead or jacketed bullets with a crimping groove or cannelure you should roll crimp the case mouth into the place provided. Taper crimp is used for semi auto loads that head space on the case mouth and the bullets have no cannelure or crimp groove.

 

[Shrinkmd]

Latest online price of Brown Bear 9mm 1,000 = $190 at AIM surplus. I enjoy my 9, but I think that full house 357 for considerably less money in components (plus the unbilled "hobby time" of reloading them all) will be a lot more fun.

Do you just throw the brass away after 5 full house loads, or do you try and stretch them out (no pun intended) with some light target loads after their magnum days are over?

Also, can someone PM me or otherwise direct me to where the best loading data is for the Oregon Trail bullets?

 

[jjohnson]

Walkalong beat me to it.

For lead bullets with a crimp groove, I roll crimp into the crimp groove.

With plated bullets, I taper crimp.

Voting with Walkalong again - I voted "both are fine" because I, too, base crimp on ammo performance requirements.....

 

[Marlin 45 carbine]

I load all cast slugs for any of the pistol rounds I load for to 'practice' velocitys, about medium I suppose.
it keeps things simple for me. I wish I had more time to shoot what I load.

 

[SteveW-II]

> Does any one know of any other .357 mag auto loader other than the Koonan?

Desert Eagle.

 

[fguffey]

ShrinkMD, I use a RCBS carbide full length sizer die to crimp some cases, this gives me the option of a roll crimp, tapper crimp or a partial full length sizer die crimp, cases sized in this manner come out identical to factory ammo, the one pistol I have that likes store bought ammo can not tell the difference and will not run on reloads, as a trade off, it is very accurate.

F. Guffey

 

[USSR]

The taper crimp die is for the guys with S&W Model 52's.

Don

 

[TheEngineer]

Is the Lee factory crimp considered a roll crimp, a taper crimp, or something else altogether?

 

[Mister_P]

Hi from Belgium

Hi,

I ve found an answer for your question, found on H n N website :

B) Taper crimp with hard .44 charges
With hard .44 charges and the recommended taper crimp the bullets are often drawn out of the cartridges left in the cylinder. As described in our range of products, you should resort to a “Factory Crimp” die in this case. With this you can choose from friction crimp through to roll crimp depending on the setting. With “roll crimp” a uniform cannelure is pressed into the bullet and at the same time the case mouth is crimped. This is the only way to obtain consistent neck tension and thus a consistent burning rate.

http://www.hn-sport.de/en/service/tips-tricks-for-reloading/reloading.html

 

[moxie]

Well, here's yet another approach. When loading .38 wadcutters (any style) or 125 gr. RN really light (< 3.5 gr. Bullseye) for target use, I use a roll crimp seater/crimper RCBS die but seat WITHOUT crimping. A properly set expander die will ensure sufficient case tension to prevent bullet setback. You just have to get the seating process to remove enough flare to allow the round to chamber easily. Nothing to it. In the RCBS instructions this is under the "Bullet Seating without Crimping" section. I have tried separate taper crimping on these rounds and no improvement results.

Otherwise, roll crimp into the cannelure as noted above.

 

[Walkalong]

With “roll crimp” a uniform cannelure is pressed into the bullet and at the same time the case mouth is crimped. This is the only way to obtain consistent neck tension and thus a consistent burning rate.

Incorrect.

Crimping does not "obtain consistent neck tension". That is the job of the relationship between the sizer and expander, in conjunction with neck thickness.

No amount of crimp (from whatever brand) can make up for poor neck tension.

On revolvers a good roll crimp aids in combustion of some powders (critical in some apps), and keeps bullets from pulling out under recoil, aided of course by proper neck tension.

Poor neck tension and a great crimp will not work properly.

That website is about their plated bullets and taper crimping said bullets. Second link to it you have posted. I am sure they give good advise on crimping their own bullets, but crimping does not "obtain consistent neck tension". It can add to good neck tension, but can't fix bad neck tension nor make it more consistent. (or less consistent)

 

[moxie]

Ditto what walkalong said. The real job of holding a bullet in the case is done by a correctly adjusted expander die, not by crimping. Seems counterintuitive, but this is probably the least well understood principle of reloading. Crimping is an aid to, not a substitute for, proper expanding. Overcrimping deforms/damages the bullet and leads to inaccuracy and shortens case life.

 

[GRIZ22]

Does any one know of any other .357 mag auto loader other than the Koonan?


Desert Eagle was made in 357 mag back in the 80s at least.