taper of roll crimp for 38 and 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.

Marc

[magnumb]

ps, not sure if this is the correct forum for a die question, please move to correct forum if needed

[Mk42gunner]

You didn't make a mistake, you just have more options with an additional taper crimp die.

Your seating die has a roll crimp shoulder that can be used either after seating the bullet and with further adjustment or at the same time as seating. Or you can seat the projectile then use the taper crimp die instead of roll crimping.

Robert

[243winxb]

Bullet with crimping groove - roll crimp.

No crimp groove- taper crimp.

Neck tension mostly holds the bullets from moving under recoil.

Test- load a cylinder full. Fire all but last round. Has the bullet moved more then .003" ? If moved a lot, more neck tension needed and/or a better crimp.

[45DUDE]

Taper crimp is mostly for a wad cutter at low velocity in target guns like a S&W 52sa. I have a taper crimp die but I use the roll crimp die and adjust to the case size <flare>down with wad cutter bullets as in no crimp. Be sure the boolit plunks. If a boolit has a crimp groove the end of the case needs to be roll crimped into the crimp groove to keep the projectile from moving forward under recoil. The more the recoil may require a heavier crimp. So- say a model 52 S&W has a tight chamber. A taper will adjust the end of the case better to make a little smaller than a roll crimp because the taper crimp covers more area. Unless you have a 38 automatic you really don't need a taper crimp die.

[magnumb]

I will have to learn how hard to taper crimp. The roll crimp seemed more obvious, you can tell just by looking. Any tips on how hard to taper crimp?

[deltaenterprizes]

I use the taper crimp on light target loads and roll crimp on full power 38s or 357 magnum loads.
The taper crimp does not work the case mouth as much so the case doesn’t split as much.
Case mouths need to be square and the cases need to be trimmed to the same length to get consistent roll crimps.

[georgerkahn]

Just to throw out another option -- I generally taper crimped my H&G cast .38 S&W special bullets for my S&W Model 52. Other .38's and .357's got a roll crimp. Entered too was the addition of a Cannelure tool when I wanted a crimp on a bullet with no cast groove.
Time moves up a few decades and I "discovered" the Lee Factory Crimp Die. I pretty much use this crimp die in all calibres, all bullet types, and have nothing but GREAT results in so doing.
On times, again they have changed -- generally with immense price increases -- but when I purchased mine they were (imho) quite inexpensive.
Just -- on the subject of crimping -- still another option for you.
geo

[TNsailorman]

I have always roll crimped revolver loads and taper crimp auto loads. Either way, to get the best results as far as consistant loads are concerned, I trim all my brass (whether revolver or auto)on the first loading but only check them for length again after 4 or 5 loads after that. I have yet to have to trim revolver or pistol brass after the first trimming. My experience anyway, james

[jetinteriorguy]

While there’s nothing wrong with using either a roll crimp or a taper crimp in the proper application, there’s a third option that basically eliminates the need for both of these and works in all situations. That’s a Lee collet crimp die. It’s pretty tolerant of varying case lengths, holds extremely well without over crimping, is easy on brass, and doesn’t cut through the coatings on copper or Hitec coated bullets.

[pworley1]

Which ever type of crimp you use, I would suggest that you don't crimp more than you need. I have found that no crimp or very little crimp is needed for most light to medium loads

[justindad]

I have had .357 Mag boolits start to move out of the case when I did a light roll crimp, and they were not loaded hot. Also, slow magnum powders need a firm roll crimp for consistent ignition. I prefer Reddings profile crimp die. I have used Lee’s collect style FCD on .357 SIG and I suspect it is harder on brass than a roll crimp.
*
.45 Colt does fine with a taper crimp, so I imagine .38 Sp would too.
*
The M die expands the brass well below the taper, to prevent swaging the boolit down to a smaller diameter. I’m moving towards custom expander plugs from Buffalo Arms, because the ideal size depends on your gun and your alloy hardness. The custom plugs are about $22. I pulled soft lead wadcutters (96-2-2 alloy) out of my brass and found they were swayed down from 0.3577” to 0.3570” (I used an expander from Redding, which I believe has the same dimensions as the Lyman M die).

[cwlongshot]

Maybe this can help.

https://youtu.be/j-T70WAkWxU

[gloob]

Whenever any visible flare from the expander is gone, it's enough crimp for these loads. But your case lengths will vary, so some will get more crimp than others. You're living with the average.

A bit deeper taper crimp will prevent setback if the bullet has a crimp groove. But this is mostly an issue with rifle and bottle necked pistol ammo shot in a semiauto. Revolvers have the opposite problem.

A roll crimp is what you want if you're loading them hot and shooting out of a light revolver. That keeps the bullet from pulling out of the case.

[1hole]

I will have to learn how hard to taper crimp. The roll crimp seemed more obvious, you can tell just by looking. Any tips on how hard to taper crimp?

Yeah; "Don't crimp too much."

The goal of taper crimping is to remove the flaring of cases that headspace off the case mouth so they can chamber easily. Rightly done, taper crimped ammo has little use in anything but autoloading handguns.

Nicely done roll crimped revolver ammo looks impressive but for most of us it's only useful in large cases containing heavy charges and heavy boolits. Roll crimping is easy to over do for good case life; roll crimps are "Split Mouth City"!

[lightman]

I prefer to roll crimp revolver ammo and tape crimp ammo for autos. But the taper crimp should work ok for your 38's.

Is it possible that your 3rd die, the seating die, has a roll crimp and that maybe you could swap the seating plug and seat with the taper crimp die without crimping and crimp with the roll crimp die. Basically just reversing the order of the 2 dies. Hope this makes sense!

[Green Frog]

For my 32 revolver loads (same as your 38 Spl but smaller) I like to use my seating die to barely remove the case mouth flare, then I have the taper crimp to final fit the cartridge profile to pass the “plunk test”. Come to think of it, when I shot PPC I did the same thing with my 38 Spls.

Back when I was loading 44 Magnums to Keith type levels I gave those cases a good roll crimp because of the tendency for bullets to back out under the recoil.

All semi auto ammo is routinely taper crimped since so many of these cartridges headspace on the case mouth.

Froggie

[Jtarm]

Bullet with crimping groove - roll crimp.

No crimp groove- taper crimp.

Neck tension mostly holds the bullets from moving under recoil.

Test- load a cylinder full. Fire all but last round. Has the bullet moved more then .003" ? If moved a lot, more neck tension needed and/or a better crimp.

This.

[metricmonkeywrench]

+1 on the Lee FCD for all straightwall pistol calibers. Heres a table to help with deciding which crimp.

[Kosh75287]

I've used both. I get tighter groups and more consistent velocities with the taper crimp.