Taper Crimp

[Hi-Speed]

When loading my 357 Magnum loads using 358429 bullets, I usually adjust OAL to 1.553” (per Lyman manual). I’ve been doing this for years when I had S&W Model 28s which cylinders were to short to accommodate the 358429 crimped in its crimping groove (I did this practice using 38 Special cases when loading 38-44 level loads). I still use a roll crimp on the 358429 and crimp over the front shoulder band an age old practice. I also like how the bullets performs seated short and it looks are reminiscent of old 357 Mag loadings with their SWC bullets.

However, I also like using Rim Rock’s 170 gr Keith SWC but when loading these “short” using Lyman OAL specs, I use a taper crimp since I’m on crimping on (not over) the first driver band. I do not crimp over their front shoulders since this would bring the OAL down to 1.525”. I never have bullet creep with a taper crimp using either the Lee or Redding taper crimp dies. Even with my standard magnum Keith SWC load using 11.0 grs of 2400 (1,130 fps avg in Ruger 4 5/8”) in 357 Mag cases, the taper crimp keeps the Rim Rock Keith’s SWC securely in place. I also get better accuracy with a taper crimp.

When using the 358156GC I crimp those in the first crimp groove always when using my std 13.5 grs 2400 load using this bullet.

I also see others use a taper crimp with cast bullets when not crimping in their crimp grooves. It was something that I was taught years ago, roll crimp in crimp grooves, taper crimp when not using the grooves.

Appreciate any your comments regarding taper crimping with cast bullets

[Hannibal]

So long as the crimp is performing it's function of preventing incidental bullet set back and accuracy/loading/feeding is unaffected then the type of crimp used is personal preference/asthetic.

[pworley1]

I usually roll crimp for rifle and revolver and taper crimp for semi-auto.

[Springfield]

I find most cast bullets are soft enough to roll crimp even if there is no groove there.

[Kosh75287]

I tend to seat bullets in one step then taper crimp them in a separate step, in .45 ACP, and in most of my .38 Spl./.357 Mag. reloads. I'd likely do the same in my other auto pistol calibers, but taper-crimp (only) dies for them are rare and expensive.
I'VE taper-crimped polymer-coated 215 gr. SAECO #58 SWCs in .45 Colt cases with good success, even in very warm loads. I used a Redding taper-crimp die for .45 ACP to get it done. Neither the .45 Colt cases nor the taper crimp die seemed to object.
Results from my Redhawk were more than acceptable. I'm finding that the SAECO #58 is a lot like the H&G #68 and the LEE 455-255-RF in .45 Caliber pistol & revolver rounds. It's easier to obtain good results than bad results with them, if the reloader does not go crazy.

[justindad]

I taper crimped .45 Colt rounds with good results. For .357 Mag, I have had bullets walking out of the case when using a light roll crimp in the cannelure, so I’d pay close attention if using a taper crimp. My bullets didn’t come out far enough to lock the cylinder, but I didn’t notice that the holes in my target formed a vertical line. Fill your cylinder with six rounds, only shoot five. Replace the five rounds and shoot them. Take the round that sat through two cylinders and measure its length. If it hasn’t moved by more than 0.002” I’d be happy (depends on powder, accuracy needs, etc)… just consider the variance in COAL you achieve in your loading and use that as a gage for acceptable bullet walk.
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I might be wrong, but I don’t think it’s considered safe to taper crimp when using H110, Win 296, or other powders than are difficult to ignite.