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crimp or not to crimp
- Thread starter buffermop
- Start date
Broad topic.
Short version:
Revolver rounds: roll crimp lead and jacketed with a crimp groove. Stay away from jacketed slugs that don't have a groove.
Auto pistol rounds: mild taper crimp.
Most bottleneck rifle rounds with jacketed slugs: no crimp.
Straight-wall or straight-taper rifle rounds with lead slugs (older rifles): light roll crimp.
Short version:
Revolver rounds: roll crimp lead and jacketed with a crimp groove. Stay away from jacketed slugs that don't have a groove.
Auto pistol rounds: mild taper crimp.
Most bottleneck rifle rounds with jacketed slugs: no crimp.
Straight-wall or straight-taper rifle rounds with lead slugs (older rifles): light roll crimp.
Well put - a rep point for you RKG. I'd like to add three things:
- Keep in mind that a taper crimp really isn't a crimp at all - you simply remove the belling that you put in with the expansion die and make the case mouth parallel with the rest of the case.
- Also, you can crimp rifle rounds if the bullet has a cannelure (crimp groove). You seldom need to crimp even cannelured bullets, but if it's there, you can use it.
I asked a similar question a while back, and did some experimentation. My crimped .223 reloads were slightly more accurate than the uncrimped rounds. I've since noted that the crimped rounds exhibit more consistent velocity than the uncrimped rounds, especially when it's cold (below 40 degrees). YMMV.
- I have a fair bit of experience loading magnum revolver rounds. These absolutely need a strong roll crimp. Some of the "magnum" powders won't burn right unless there's lots of crimp. Also, the bullets can come out of the cases if there's insufficient crimp. If we're ever shooting together, remind me to show you what happens to an improperly crimped .460 S&W Magnum round.
![[shocked]](/xen/styles/default/xenforo/smilies.vb/007.gif "Shocked [shocked]")
I use a Lee Factory Crimp Die (FCD) on all my handgun cartridges (.38 Super, .40 S&W and .45 ACP). Note also that the .45 loads are used in both autos and revolvers.
Even with poly-coated bullets, there have been no problems with setback. While the roll crimp is the traditional revolver practice and may be necessary for magnum loads, I use the roll crimp only on .38 Special/.357 loads. That is only because it's been so long since I've loaded any, I never got an FCD for them!
The Lee FCD die for traditional "revolver" rounds (.38/.357, .44 Mag/SPL and .45 Colt) actually applies a roll crimp.
Could you explain how it achieves that? I use FCD's because the carbide ring resizes the entire cartridge, greatly reducing FTF's. How does the roll crimp get applied?
Or are you referring to the inner, upper collar which the top screw
applies to the case mouth?
That's the one. Screw it down far enough and it roll crimps. I believe that the geometry of this part is different for traditional revolver calibers as well.
I do not crimp my rifle rounds at all.I apply a slight taper crimp to my pistol handloads(auto's only).I currently do not reload any of my revolver calibers.
BTW-Srivener,thank you for the info on the Lee Factory crimp die.I recently picked one up for .45acp and I love it.It really works well and speeds up the process quite a bit loading these on a single-stage.
![[smile]](/xen/styles/default/xenforo/smilies.vb/001.gif "Smile [smile]")
I have 3 single shot rifles 2 Browning 1885 and a Shiloh Sharps and I don't roll crimp for them. I use a redding profile crimp die and adjust it to just take the bell out of the case. IIRC from one of the reloading manuals crimping for SS rifles is not needed.
Because there is no ammunition is an SS gun other than the round in the chamber, there is no set-back from recoil. This is a significant factor in guns with tublular magazines, where spring tension and the weight of other cartridges increase the set-back forces working against the bullet.
Fooped
Resident HK Guru
On this topic, is there a safe way to load the "plated" bullets that don't have the crimp groove? I have noticed on several occasions that with .357 and .44 Magnum I get pieces of the jacket flying back out of the forcing cone back toward the shooter!
Needless to say this isn't good.
I have tried putting much less of a crimp on the rounds, and this seems to help, but I'd like to play it safe here. Should I use these bullets for .38 special only?
Help!
Needless to say this isn't good.
I have tried putting much less of a crimp on the rounds, and this seems to help, but I'd like to play it safe here. Should I use these bullets for .38 special only?
Help!
Crimp and side spit should be entirely unrelated issues. I'd have someone take a look at the timing, end shake, and related parameters of any revolvers that are side spitting more than a little gas.
