Roll-vs- Taper

[The Kidd]

Hey, I'm a new guy here. I started out loading for rifles so my kids and I could shoot more and better rounds. Then I thought it would be fun to load some handgun rounds. Then I started loading lead 'cause it's cheaper. So through natural progression I started, recently, to cast boolits. So far .45 230gr trunce cones that work great. The point I've been leading up to is that I just cast some .358 158gr SWC tumble lube boolits. So far all revolver projectiles have had clear/obvious canneleur(sp). These .358s do not. So do I order an RCBS taper crimp die or just try to roll crimp the top lube groove? I've really tried to puzzle this out by reading this forum but I can't find a clear answer. Thanks.

[jmort]

"...roll crimp the top lube groove"

That is what I do.

[winelover]

General Rule of Thumb.

Roll crimp for revolvers, taper crimp for autos.

Winelover

[The Kidd]

Thanks for your replies. Does anyone else use a Lee tumble lube mold and understand the problem? I will try to roll crimp but that groove is pretty small. I guess I'll test drive 'em in my Blackhawk to see if they stay put.

[ffries61]

You might consider crimping over front shoulder, but check COL.

Fred

[sparky45]

I haven't had any problem with taper crimps for my 45LC Blackhawks, however, I load light plinking loads. My rule of thumb is to roll a crimp for my lever action rifles and taper a crimp for everything else. Again, I load "light" loads.

[The Kidd]

Just in case anybody is interested... I did in fact roll crimp the top lube groove and it worked just fine. Thanks.

[Mike Kerr]

I am interested, I just didn't see your post on the initial go round. Its only worth a little bit but I was going to say "roll crimp to the top groove if possible" cause thats what I would try to do.

regards,

:-D:-D:-D

[6bg6ga]

Used to load for my brothers Desert Eagle 357 with some rather nasty full loads with roll crimp and no problems.

[USMC87]

Roll the revolvers and taper the autos.

[farmallcrew]

Another vote for, roll the revolver, taper the auto.

[unique]

I user taper for all my 357 mag & 38 special loads and never had any problems after many thousands of rounds of various types of cast and jacketed bullets. The reason I selected taper was there was a sale on the tapered 357M/38SPCL RCBS dies a long time ago when I was starting out so that is what I bought. Probably on sale because no one uses taper crimp for 357 Mag...

Anyway, if I was going to do it again I would certainly buy the taper crimp, especially for cast. I believe it works the brass less and more importantly is less likely to deform the bullet since all my crimp does is to take the bell out and forms an ever so light taper crimp which is enough to hold the bullet under all the conditions I used it. Another thing is I believe varying length of brass is less of an issue with taper crimp than roll crimp and I have never trimmed my brass, even after 20-30 reloads. In other words the taper crimp makes a more uniform crimp. Used these loads in all manners of revolvers including SP101 and up to 180gr loads and never had a problem with bullet 'walking' from recoil.

The one place where taper crimp did not work well was with shot capsules in 38 Spcl in SP101 but I read in the product comment sections for the Speer capsules that the roll crimp didn't hold the capsule either so not really all that telling. Actually another person wrote that the roll crimp was more likley to crush the shot capsule than taper crimp so their suggestion was to go with taper crimp.

[6bg6ga]

Used to load for my brothers Desert Eagle 357 with some rather nasty full loads with roll crimp and no problems.

I will add that the roll crimp was all I had at the time. Either will work fine on the 38/357

[mdi]

I started casting with Lee's T/L mold for .44. I liked to roll crimp into the 3rd or 4th groove down from the first driving band. In my mind I have a portion of the bullet that is full diameter entering the forcing cone/barrel and with a full diameter, it gets a straight start. I cannot verify if my thoughts are correct, but I got several 2" groups @ 50' (indoor range) shooting the 240 Lee T/L bullet over some 2400 in my S&W 629 and Dan Wesson 44H...

[jmort]

"Probably on sale because no one uses taper crimp for 357 Mag..."

Everyone will have a preference. For revolvers, roll crimp makes sense. Any bullet jumping crimp would be a disaster in a self-defense situation.

[BoolitSchuuter]

Roll or taper crimp is actually determined by how the cartridge head spaces in the chamber. Cartridges that headspace on the rim generally are roll crimped, but a taper crimp will work also. The roll crimp will help improve consistency by holding the boolit that fraction of a second longer to get the slower powders burning efficiently.

A taper crimp is generally used on cases that headspace on a shoulder and MUST be used on cases that headspace on the case mouth (450 Bushmaster being one example).