I'm loading my first batch of 38 specials, and I know that I need to roll crimp into the cannelure. Question is, do I need to completely cover the cannelure with the mouth of the case? or do I center the mouth in the cannelure? How does this work?
I do the half-way crimp also. Do it in slow increments until you get a proper crimp; it's not difficult to over-crimp sometimes and then you'll have some useless cartidges and ruined brass. That's experience speaking here...LOL
Okay, I just did five for my first batch. I crimped to where you can tell the end is roll crimped, for sure. The cannelure isn't deformed at all, so is this ideal, or should I see some evidence of the crimp in the bullet?
The mouth visibly bends in very obviously...is this enough?
__________________
I'll keep my freedom, guns and money. You can keep the "Change."
Last edited by Airweight38; 08-02-2008 at 07:45 PM.
I had to blow-up your picture to be sure, but your crimps are what the Speer manual call's "step-down crimps." Instead of just rolling the case mouth inward until it meets the surface of the bullet in the cannelure, it actually goes down further on the case and creates a small section of the case mouth that is cylindrical, resting agains the cannelure surface. Speer recommends that method for really hot loads in revolvers, and designs their NEW bullets for it by making their cannelures flat bottomed instead of curve bottomed.
So, Airweight38, if you are shooting bullets with a cannelure that is flat-bottomed, you can do a step-down crimp if you want to. Speer says to position the case mouth so that it all but competely covers the cannelure and set the crimp die to reduce the case diameter for about the length of the cannelure (allowing for case thichness so that you are not deforming the bullet).
BUT, if you want a plain roll crimp (which should be enough for 38 Specials), then position the case mouth in the MIDDE of the cannelure and roll it down to just touch the bullet's surface inside the cannelure. The idea is to roll it over the shoulder of the bullet where if is decreasing to the crimp diameter.
These two crimps are both made with the same roll crimp type die. The step-down version is definitely harder on the brass, and I have not found it to be necessary, even in my magnum loads. Maybe those guys shooting Casulls or 460s need it, but my 357s and 44 Mags don't.
Jimkim,
I had to blow-up your picture to be sure, but your crimps are what the Speer manual call's "step-down crimps." Instead of just rolling the case mouth inward until it meets the surface of the bullet in the cannelure, it actually goes down further on the case and creates a small section of the case mouth that is cylindrical, resting agains the cannelure surface. Speer recommends that method for really hot loads in revolvers, and designs their NEW bullets for it by making their cannelures flat bottomed instead of curve bottomed.
So, Airweight38, if you are shooting bullets with a cannelure that is flat-bottomed, you can do a step-down crimp if you want to. Speer says to position the case mouth so that it all but competely covers the cannelure and set the crimp die to reduce the case diameter for about the length of the cannelure (allowing for case thichness so that you are not deforming the bullet).
BUT, if you want a plain roll crimp (which should be enough for 38 Specials), then position the case mouth in the MIDDE of the cannelure and roll it down to just touch the bullet's surface inside the cannelure. The idea is to roll it over the shoulder of the bullet where if is decreasing to the crimp diameter.
These two crimps are both made with the same roll crimp type die. The step-down version is definitely harder on the brass, and I have not found it to be necessary, even in my magnum loads. Maybe those guys shooting Casulls or 460s need it, but my 357s and 44 Mags don't.
SL11
They arent technically MY crimps they came from a Google search for ROLL CRIMPS. The article was about ROLL CRIMPS and that was the picture they used. It is Winchester factory ammo with roll crimps. Hahahahahahaha!!!!!! Man that is something else. J/K
__________________
For info purposes only, use it at your own risk. JFKimmons and G&G aren't liable for it's misuse.
BUT, they are on cast bullets, which have a different shape to their crimp grooves than the cannelures pressed into jacketed bullets.
The cast crimp grooves are usually shaped more like this:
Code:
|_
/
|
while the cannelures on a jacketed bullet are more like this:
Code:
| |_
) or _|
| |
(Sorry about the course graphs; hopefully you can see a traingular shape verses a rounded or flat-bottom depression.)
Anyway, the roll crimp can go farther up a cast bullet's crimp groove than a round bottom cannelure to "hug" the shoulder of the bullet where it rounds into the depression. So, it still looks a little different than the jacket bullet situation that the OP was requesting advice for.
Thanks? Oddly enough I thought a post with "Here is a picture titled roll crimps with cast bullets" written over it wouldn't need someone to explain that it was a picture of cartridges loaded with cast bullets. I thought I would just throw it in so there would be an example using cast bullets. I didn't think it was that confusing. Nice diagram.
__________________
For info purposes only, use it at your own risk. JFKimmons and G&G aren't liable for it's misuse.
Sorry, I'm not trying to be critical of somebody who is trying to help.
But, the OP was initially asking where to put the case mouth in relationship to a cannelure on a jacketed bullet in order to get a proper roll crimp, and the pictures he was getting were step-down crimps or DEEP roll crimps on cast bullets. Either could be misleading to somebody who needs to ask the original question, so I am just trying to help him by being clear and explaining the differences using a roll-crimp die in different ways on different bullets.
Thanks for the help from both of you. Both POVs have taught me something. Based on my own experience, coupled with this info, it sounds like I will probably never need a step-down crimp for .38, .357 or .44s. At least that's my perception? How about this: I've noticed when I crimp my 38s, too little doesn't show much of a shoulder. Too much and it looks like it goes in and plateaus and there's actually a flat part of the mouth against the cannelure.--That's a step-down crimp, isn't it? So an evident shoulder with no flattening of the mouth is a normal crimp, then.
__________________
I'll keep my freedom, guns and money. You can keep the "Change."
Last edited by Airweight38; 08-08-2008 at 03:09 PM.
Sorry, I'm not trying to be critical of somebody who is trying to help.
But, the OP was initially asking where to put the case mouth in relationship to a cannelure on a jacketed bullet in order to get a proper roll crimp, and the pictures he was getting were step-down crimps or DEEP roll crimps on cast bullets. Either could be misleading to somebody who needs to ask the original question, so I am just trying to help him by being clear and explaining the differences using a roll-crimp die in different ways on different bullets.
SL1
I thought the original question was this:
"Question is, do I need to completely cover the cannelure with the mouth of the case? or do I center the mouth in the cannelure?"
I thought the first picture answered this question. That is why I posted it.
__________________
For info purposes only, use it at your own risk. JFKimmons and G&G aren't liable for it's misuse.
Help! Question about Cannelures 
