crimping 38's

mrmiskin · #1 03-24-2008, 07:36 PM

I have started reloading some 38's and have a question. I used the expander die and funnel to expand and charge the case in one step. Loaded everything ok but the question is do you have to crimp after using the expander die or can you seat the bullet and be done with it?

Rocky Raab · #2 03-24-2008, 08:21 PM

If you have tight cylinders, the expanded case mouths may not even enter. I find that almost all expanded cases have to be bumped back to at least parallel - and a crimp of some kind is much better.

Ignition and powder burn are also MUCH more consistent with a crimp.

Jack · #3 03-24-2008, 08:38 PM

Ditto

mrmiskin · #4 03-25-2008, 08:48 AM

Thanks and once again you are correct I had to crimip to get them to chamber. I am learning something new every time i reload and when i get stumped this is the place to get the quality information.

Adam Helmer · #5 03-25-2008, 10:14 AM

mrmiskin,

You got good advice.

Do you have a good, current reloading manual such as Lyman's? All current reloading manuals give a lot of good advice with photos describing the reloading process. If you have not read that material, I think you should take the time to do so to help frame future questions.

Good luck reloading.

Adam

Gil Martin · #6 03-25-2008, 06:05 PM

These folks are right on. All the best...
Gil

270man · #7 03-25-2008, 11:51 PM

I faced this issue a few years back. My seating die was adjusted to just remove the bell from the expanded case. Had no problems with chambering cartridges but I was worried about consistent ignition. I then began roll crimping my loads but noticed big differences in the crimps. A check of case lengths (measured after re-sizing) revealed significant differences. This meant that I would have to trim all my cases, which is a real pain for 38spcl and 357Mag.

I was astounded when I found that none of my cases were as long as the trim-to length specified in the reloading manuals. I even found this to be true with several batches of brand new cases in 38spcl, 357Mag, 40S&W and 45ACP. I asked advice from various sources and got different answers. Most of them involved a lot of work -- measuring, sorting and trimming.

The problem was solved when I found an article recommending taper crimpng instead of roll crimping -- no bothering with trimming to equal case length. I immediately started doing this and have never looked back. I conducted accuracy and velocity tests in my 357Mag revolvers and could tell no difference between the two crimping methods.

The only caveat I have is that the big boomers (i.e., 44Mag and up) might need heavy roll crimping. Can't say for sure since I don't reload for anything bigger than 41Mag.

270man

Jack · #8 03-26-2008, 02:02 AM

I've also found that in many pistol cartridges, cases never get to maximum allowable length, and never seem to grow. Many years ago I measured 1,000 9MM cases, and never found one that was max length. (that job was no fun at all)
Taper crimping is recommended for auto pistol cartridges that headspace on the case mount, like the 45 ACP, 9MM, 40 S& W, etc.
For revolver cartridges, roll crimping is usually recommended, but taper crimping can work well in some situations. I taper crimp 38 wadcutter loads.
270man, just to be annoying, I'll point out that case length still matters with taper crimping. A long case goes farther into the taper crimper, and gets crimped more, than a shorter case, assuming you don't adjust the die. However, the difference is small enough it isn't likely to show on the target. If you're a really good shot, and have a really accurate pistol, it might.
I would be a little wary of taper crimping a full power 357 load. But if you've tested it, and your load works, great.
What I do is roll crimp any revolver cartridge that has much felt recoil- and that might not be a magnum cartridge. A 38 or 44 Special, or 357 magnum in a light compact revolver can be a worse kicker than some of the bigger magnums in heavy revolvers.