Roll vs Taper

Hakaman · Post by **Hakaman** » Thu Dec 02, 2010 12:31 pm

I have been struggling getting my 38sp loads to where I want them. All along, I have been using a "taper crimp" on them. The results, regardless of the powder level, were inconsistent burn and power. Using 5.8-6.3 gr of Win AutoComp, with a plated 125gr bullet, nothing seemed to comfortable. That is, until I used a "roll crimp". The reason I didn't use a roll crimp before is that my Lyman dies came with a "taper crimp" die. I didn't realize, until Mr Greener mentioned it, that the bullet seating die also doubles as a roll crimp die. Now that I have been roll crimping my 38's, they are shooting more consistent with good power and burn rates. Now I have "backed off" on the amount of powder necessary. All in all, a much nicer round to shoot.
Haka

blue68f100 · Post by **blue68f100** » Thu Dec 02, 2010 4:24 pm

That must be a special set of dies to have a taper crimp on a 38 spl. All that I have seen have had the roll crimp.

bgreenea3 · Post by **bgreenea3** » Thu Dec 02, 2010 4:38 pm

I do beileve that the "factory crimp die" that lee sells will put a taper crimp on a 38 spl, so they are out there. but most revolver rounds use a roll crimp, I think that it gives resistance to the bullet leaving the case and increases the pressure so you get a more complete ignition of the powder.

perazzi · Post by **perazzi** » Thu Dec 02, 2010 10:10 pm

As bgreenea3 says, My understanding has always been, roll crimp for revolvers, and taper crimp for semi-autos which headspace on the case mouth.

the roll crimp prevents the bullet from moving towards the muzzle under recoil and locking up the cylinder.

bgreenea3 · Post by **bgreenea3** » Fri Dec 03, 2010 4:41 am

perazzi wrote:As bgreenea3 says, My understanding has always been, roll crimp for revolvers, and taper crimp for semi-autos which headspace on the case mouth.

the roll crimp prevents the bullet from moving towards the muzzle under recoil and locking up the cylinder.

or in lever actions it keeps the boolit from being jammed into the case in the magazine.

greener · Post by **greener** » Fri Dec 03, 2010 7:32 am

Lee bullet seating dies do the role crimp. I suppose, if you were going for hot loads, overcrimping could be a problem.

I've read about adding fiber to the reloads to improve powder burn, but I can't find it this morning.

Hakaman · Post by **Hakaman** » Fri Dec 03, 2010 7:07 pm

Here's the set I have:
http://www.lymanproducts.com/lyman/dies ... e=6&die=20

I pretty much won't be using the taper crimp any more. Live and learn.
Haka

bgreenea3 · Post by **bgreenea3** » Fri Dec 03, 2010 10:48 pm

I like these.....http://www.leeprecision.com/cgi/catalog ... crimp.html

I lnow i'm going to get some flak from folks who love RCBS, Lyman, Or Dillion. but I've used all of them and Lee's dies are as good as the others at a cheaper price and I like some of their features.

Post by **Bullseye** » Sat Dec 04, 2010 7:01 am

I've used Lee dies for years. I've got no complaints about them, they do the job well.

R,
Bullseye

greener · Post by **greener** » Sat Dec 04, 2010 7:39 am

I've been satisfied with my Lee dies. They are the only ones I've had and, maybe, I just don't know no better.

I haven't seen much in my reloads to indicate that I should be doing the taper crimp except for .45 ACP. I have Lee Factory crimp dies but only use the .45ACP die. I had trouble getting consistent chambering in my Taurus and P90 until I used that die. 9mm reloads seem to have no problems with the roll crimp. I have a Lee Pro 1000 which only takes 3 dies, so the factory crimp is a separate operation and I'm too lazy to perform an operation I don't need.

Hakaman · Post by **Hakaman** » Sat Dec 04, 2010 8:35 pm

I've used Lee dies for years. I've got no complaints about them, they do the job well.

R,
Bullseye

Garrulous Maximus
I've been satisfied with my Lee dies.
9mm reloads seem to have no problems with the roll crimp.

I see you two, and many others like the Lee dies. Include me in that group.
I was hesitant on purchasing Lee dies when I was wondering which manf to
buy for my 223 reloading needs. I have dies from Lyman, and RCBS, both of which
are nice die sets, but I thought I would give Lee a try. I have loaded about 2000 223's
so far without any problems, the dies are a great bargain and do the job as well as my other dies.
I also purchase Lee's for my 9mm and love em, I wouldn't hesitate to recommend them to any body.
Greener, you say you roll crimp 9mm's ? Don't they head space off the mouth? No problems?
thanks, Haka

greener · Post by **greener** » Sat Dec 04, 2010 8:40 pm

the roll crimp hasn't been a factor in the M&P or the SR9. I don't do a heavy crimp.

blue68f100 · Post by **blue68f100** » Sun Dec 05, 2010 2:08 pm

If you have not tried any Hornady Dies you way want to give them a try. I own a mix of dies but I seam to like the hornady's the best. The sizing is much smoother over RCBS and Lee. And they still have the rebate going on too.

Magnum calibers require a heavy roll crimp. Slow burning powders some times need it too to help build up the pressures for a even burn. I normally let the bullet design dictate which to use.

greener · Post by **greener** » Sun Dec 05, 2010 8:22 pm

Finally remembered the filler bit for more complete powder burns.

The recommendation is a bit of polyester fiber in the case to cause more even and complete burn rate. Over on rugerforum.net

http://rugerforum.net/reloading/10444-c ... wegan.html

http://rugerforum.net/reloading/18442-q ... iller.html

I've intended to try it, but haven't found that round tuit yet.

Hakaman · Post by **Hakaman** » Thu Dec 09, 2010 3:29 pm

I've used Lee dies for years. I've got no complaints about them, they do the job well.

I just received a set of Lee 45LC dies in the mail from Midway USA today. It's amazing how fast they ship things out to you.
Anybody have any "favorite loads" with a 255gr bullet and W231 powder ?
Haka