I am now loading for .38 Spec. in a revolver. A taper crimp in my .45 ACP Auto. works as suggested. I have a Dillon SDB and will have the .38 conversion kit in a few days. What kind of crimp dies comes with it? My first bullets will be full WC and I was told to roll crimp them. Will my Dillon die do this, I have LRN bullets coming, these will need a taper crimp, I think. Will my Dillon die do both?

Thanks again for all the VERY good information I have received.

Jim

Roll crimp is the way to go for revolvers and your dies should come that way. 38 special with mild loads could probably get by with no crimp at all with light loads in a normal weight firearm. Case neck tension would be enough to hold the bullet in place.

Cheezywan

Dies designed for the 38 special will roll crimp your cases. All the revolver dies are designed to roll crimp to keep the bullets from backing out and locking the cylinder under recoil. I like the Lee four die revolver die sets that allow me to seat and crimp in separate operations. Dillon makes good dies.

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Bob from Idaho

Aside from how crimp helps powder to burn, there are differnces in how revolver and semi-auto rounds are subjected to recoil.

Semi auto forces try to press the bullet back into the case...they want to telescope the round. Being smacked around in the magazine under recoil and running into the feed ramp want to force the bullet back into the case...a taper crimp does a good job of avoiding this.

Revolvers try to jerk the bullet forward out of the case by inertia. The cases in the cylinder move back with recoil, and just like an inertia bullet puller, the lead bullets want to stay still. A roll crimp (when there is a groove on the bullet to crimp into) seems best at stopping this motion.


In light recoiling ammo, either type will work. With pure wadcutter .38 loads, a taper crimp is strong enough to stop bullet motion AND makes loading a bit easier (the flush seated bullet and case mouth is reduced in diameter a little bit, making it easier to chamber).

Since .38 Special wadcutters are fired in both self-loaders and revolvers, both kinds of crimp are available for it. I shot taper crimped revolver target loads in matches for a number of years without problems. These were 3.2 grains of Bullseye under 148 grain wadcutters in .357 Magnum cases. The combination of gun weight being high enough and the load being light enough kept the recoil below anything that would pull the bullet. In a lightweight revolver, I expect the roll crimp would be necessary.

I opt for taper crimps when I can get away with them because the cases last so much longer before they start splitting at the mouths. However, there are circumstances under which that is just not good enough, and magnum loads are definitely one of them. That is not just from the standpoint of avoiding bullet pull, but also to have high enough start pressure for a load of slow powder to start burning well and consistently. Some low recoiling loads just seem to be more accurate with a roll crimp, and that will be up to you to test for yourself.

I don't know whether the SDB .38 Special tools come with roll or taper crimp standard? My SDB is only making .45 ACP's, so it has a taper crimp die. The SDB can only use Dillon's special dies, so you'll have to check with them if you need to make a change?

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Nick

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i always roll a crimp in my lead swc reloads... the lee speed dies i have( i bought them several years ago and i like em alot!) will taper crimp and roll crimp when you want...i use bullseye and it's nice to have a nice crimp rolled in to the cannelure of the lead bullets aspecially when loading .357 magnums for my model 27.......