Crimping Pistol Bullets - A Discussion

[oscarflytyer]

I do and have always crimped ALL/EVERY handgun cartridge. Autos/headspace on the rim (45 ACP) get a very closely mic'd taper crimp. Cast bullets in straight walls (44-40/45 Colt/44 SPC/38/357/32, etc) all get a healthy roll crimp. My reloads with crimps shoot great and accurately, and almost never get a smoked case mouth (of course, bullet size helps!).

With the above, I have started using the Lee Carbide crimp dies. So far, I really like them. I had a slight shell holder cant issue in one of my presses (old vintage BAER I was gifted - love it because three silos and can set it up with two dies to bullet seat in one and crimp in other) that I didn't catch. But it seems, from shooting results, that the carbide crimp dies corrected the issue. I am sold on them. And now that I shimmed the shell holder to true it up, can only get better.

[bluetick]

My understanding, which is admittedly limited, is that there is a general rule of thumb which calls for taper crimping auto-loader cartridges and roll crimping revolver cartridges. This is, strictly speaking, in regard to pistol loads.

[Ohio3Wheels]

Pistol, revolver, single shot or rifle crimping isn't necessarily about bullet retention. Some powders simply perform better if the pressure builds slightly before the bullet leaves the case. I suspect but can't prove except anecdotally that a lot of problems folks have with under performing powders are due to insufficient pressure during the contained burn. Once it leaves the muzzle it doesn't mater but there's no real advantage to a big muzzle flash.

Make smoke,

[kaycee]

Once it leaves the muzzle it doesn't mater but there's no real advantage to a big muzzle flash.

Make smoke,

If you've never been (temporarily) blinded from muzzle blast by a S&W .460 using full-house loads you might change your mind. Everyone close-by will take notice, stop shooting and will have a big grin on their face and possibly yell a few expletives.

Yes, big booms are cool at times...

[Ohio3Wheels]

Oh, I know, I shot a 10" Contender in 357 Herret in IHMSA competition. I could almost stop matches.

Make smoke,

[RBHarter]

Well I've wanted to stay clear of this one .........
I shoot almost exclusively cast and paper patched bullets in everything I have had to shoot .
The heavy roll crimp is hard on cast diameters so as a rule I use just enough to prevent magazine set back in tube feeders . Stack fed guns whether blind or removable box or clip fed generally get whatever crimp is applied to cases over .003 short of chamber length . Heavy crimps will cut paper patches , it's not a danger but it spoils accuracy .

Taper crimps I like but just to flatten the flair . Autos that headspace on the mouth in a full cut chamber can miss an over crimped mouth .

I avoid powders where I can that need a full pressure head to get going so the above works for me . If I need that in a rifle I load to touch the lands where I can .

I don't like the post sizing FCD dies , they just don't play well with fat chambers that like a fatter bullet . The collet type are awesome and I love them for 358 Win and 45-70 . My 45-70 brass runs long so there is a full radius when I crimp those so no cut paper . For the 358 , 308 and 30-30 it's more about crimp control because it doesn't depend on case length for crimp setting .

I mostly just remove flair rifle or pistol . I can't really give an " I always do this" answer I load for 5 actions , 17 calibers , straight , tapered , bottle neck , rimmed , belted ...... No rebated yet , and paper cartridges . Although the paper cartridges are more a passive tool making thing at this point as I explore the minutiae of the combustible cartridge and search out a proper bullet for the rifle .

[Macd]

Reread whole thread and lot of good information. I now taper crimp all rimless handgun rounds regardless of bullet composition or type. Since I don't trim most handgun brass and load a lot of cast with the necessary flare for seating, taper crimping simply removes any flare and reduces the chances of setback . I roll crimp all rimmed cartridges used in my revolvers. A jammed cylinder in a .45 Colt taught me that lesson. That same revolver has the cylinder conversion for 45 ACP without moon clips. They get the same tapered crimp as if being used in my 1911. Cast rifle bullets I load to touch the lands and just barely FCD or roll crimp out the seating flare. Jacketed rifle bullets get at most a light crimp and only if I am using a slow powder in a light load. My experience is it reduces SD. All, to my knowledge, military rifle ammo is crimped, most heavily and many also are sealed. The Swiss GP-11 cartridge is a good example. It has a snug crimp as it was also used in automatic weapons but in a rifle it is one of the most accurate military cartridges ever produced. Go figure

[horseman]

And then there's the part about tests I've read that have shown in "some" instances a primer has enough power to "jump" a bullet before powder ignites and can cause some issues (ES, SD, and other alphabet stuff ) Think I'll read up on that some more as I hadn't thought of it in quite awhile but this has brought it back to memory. That said I crimp everything I reload. A taper crimp, no matter the degree, is still a crimp. Like others I use a good roll crimp on all my revolver rounds as I've also had a couple tie up on me from bullet jump. There have been tests done from reliable sources as far as crimp, no crimp, to accuracy, consistency, and some things probably most of us don't worry about. If they go bang, hit what we're aiming at, most are pretty happy.