.38 Special LSWC reloads - Crimp issues?

Viper22

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I loaded my first batch of .38 Special tonight. Everything went fairly smooth, except for a slight issue with the crimp. I'm loading 158 grain LSWC's over 3.4 grains of Titegroup. I have the OAL at 1.460 +/- .005 and the crimp is at the crimp groove. What I noticed is after crimping there is a slight burr on the end of the brass, that flakes right off. I took the first 10 reloads to the range, and they all went bang. I also came back with all my fingers.

The only thing I can think of doing is backing the OAL to 1.465 or 1.470 and seeing if the crimp is still in the crimp groove; and seeing if it takes care of the burr.


Here's what the reloads look like:

IMG00146-20110531-2028.jpg
 
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When loading lead bullets you crimp the case mouth into the
"crimp groove", not a cannelure. A cannelure is a ring of vertical striations stamped around the base of a jacketed bullet. Also, you need to "roll crimp" to get the brass to enter the crimp groove. Maybe its just my eyes, but your rounds look like they have been taper crimped rather than roll crimped, or your not using enough roll crimp. A properly executed roll crimp "rolls" the brass of the case mouth into the crimp groove. This give the case mouth a rounded shape where it enters the crimp groove.
 
Apologies for using the wrong terminology. I'll edit my post.

The dies I'm using are a 3 die set from RBCS. Probably just not enough crimp. I'll make adjustments tomorrow and see how it comes out.
 
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PS A roll crimp into the crimp groove is used to secure the bullet against movement during recoil. This is important in hot, heavy recoiling loads. For light target loads a roll crimp really isn't necessary, a taper crimp can be used. The taper crimp squeezes the case mouth against the body of the bullet (not into the crimp groove) and provides enough tension to secure light loads. The advantage of the taper crimp is that it deforms the brass less than the roll crimp. This reduces the amount of splitting at the case mouth during successive reloads. I don't load a lot of revolver ammo and all of it is relatively light for PPC and steel competition. All I use is a taper crimp. To check the effectiveness of your crimp fire three or four rounds out of a full cylinder. Eject the unfired rounds and check the OAL, if it hasn't changed your crimp is OK for that load.
 
Overcrimping isn't good either. If you crimp too tight, you'll reduce the diameter of the cast bullet to the point where the bullet won't seal the barrel correctly, and you'll have horrible leading.

I've discussed the "test" for a good crimp many times.

Eight feet from a blank piece of paper, fire a round. If you only get a hole, crimp is fine. If you get a hole surrounded by a gray spiral shape, crimp was too loose. The spiral is unburned and burning powder running down the barrel, and being deposited by the lands and grooves.
 
Is the COAL correct? When I load 45 Long Colt LSWC I find the crimp is very close to the base of the cone. 38 may be different? Not sure, but if they were very long they would not rotate in the cylinder. HUM, let us know how it works out. Back to the lesd vs brass question.
 
If you crimp too tight, you'll reduce the diameter of the cast bullet to the point where the bullet won't seal the barrel correctly, and you'll have horrible leading.

This can't happen. You can get leading for other reasons, but you can't make a crimp die reduce the bullet diameter to the point where it will make it undersized if it wasn't already.

If its brass, you might be crimping too much.

I can't envision how this could happen either.
 
I disagree. Especially notorious with TAPER crimp dies, but it can also happen with roll crimp. Be especially careful with Factory Crimp Dies with cast bullets.
The driving band, the most important part of the cast bullet in terms of diameter, is UNDER the brass.

This can't happen. You can get leading for other reasons, but you can't make a crimp die reduce the bullet diameter to the point where it will make it undersized if it wasn't already.
Quote Originally Posted by DukeInMaine View Post
If you crimp too tight, you'll reduce the diameter of the cast bullet to the point where the bullet won't seal the barrel correctly, and you'll have horrible leading.
 
How? Forget the fact that he's using a roll crimp die. Take a look at the length of a 158gr .38 bullet. Even if you tried, you can't force a cartridge far enough into the die for the crimping shoulder to reach the bottom of the bullet - the die is too long. Even if the die was short enough, the force required to do it would crush the case before it did . Not to mention that even a newbie would notice that something wasn't quite right.
 
E/C, with all due respect, you have been reloading a while now. But you're somewhat new to casting. And, some of these folks who are asking questions are new to both.

It's one of the reasons why a lot of new reloaders, using commercially cast bullets, complain of severe leading.

Newbies don't always notice something wrong. Heck, why do we get so many newbies asking so many obvious questions? Just saying.

Like I said, the worst of it happens with cast bullets with taper crimped brass. Or, roll crimped with factory crimp dies. Both of those can squeeze the driving band smaller. Side pressure not end pressure.
 
The burr is brass flaking off one edge of the end of the case. I have a good amount of bell on the cases. One thing it could be is too much bell. I don't know if this would cause the die to pull a burr when crimping.

Duke, I'll try the paper test when I get a chance.
 
This can't happen. You can get leading for other reasons, but you can't make a crimp die reduce the bullet diameter to the point where it will make it undersized if it wasn't already.



I can't envision how this could happen either.

I respecfully disagree. I was a commercial caster for over ten years and had to deal with dissatisfied customers and accuracy was often an issue. I encounterd more than a few reloaders who crimped their 9mm (130 gr rn) to the point that the diameter of the bullet was reduced and accuracy suffered. They looked like Coke bottles!

PS the bullet were industry standard 92/6/2.
 
I don't doubt that over crimping can affect accuracy. I've seen it and done it myself.

I do doubt that a 158gr LSWC can be roll crimped enough to reduce the bullet diameter to the point where it will both chamber in the revolver and cause leading.

The burr is brass flaking off one edge of the end of the case. I have a good amount of bell on the cases. One thing it could be is too much bell. I don't know if this would cause the die to pull a burr when crimping.

Duke, I'll try the paper test when I get a chance.

Yeah, if you're over belling you could be creating a burr when the over-belled brass is pushed into the seating die. Try sizing and belling a case and then manually pushing it into the seating die. If the mouth of the belled case won't easily fit into the seating die, it might be drawing a burr on the way in. If so, see if you can get away with slightly less bell.
 
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I usually put just enough bell in the brass so the bullet just sits in the case comfortably prior to seating.
Any more is overworking the brass. You are doing good so far if this is your only problem. It looks like
your crimp is fine. The rim of the brass should be flush or almost flush with the cast bullet after crimping
in the crimp groove.
 
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While your photo is a bit blurry it appears that you have not crimoed into the bullets crimping groove and therefore you are shaving brass.
 
I think I figured out my problem.

It was the press. The linkage that connects the handle to the ram was a little on the loose side. This allowed for side to side play of the handle & ram, causing the brass to catch the crimp shoulder in the die too much on one side.

I snugged up the linkage some, and this kept the handle nice and straight through the entire movement. Loaded some more .38's and no burr! Noticeable difference in feel too. Before, I could feel the case mouth "catch" on something before crimping. Now it goes nice and smooth.
 
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