Crimping on the driving band?

[Irelander]

To start off, I am loading for my 44MAG (629) and 44SPL (Ruger Vaq). I have a cache of 240 LSWC bullets and I am loading them over 5.5gr of Bullseye for a nice light target/plinking load.

I remember reloading some 45ACP LSWC rounds with my long gone buddy and he always seated the bullet down so that the driving band was just barely sticking out above case and he crimped it right there. Back then I never thought about it. But now that I am reloading and reading about crimping into the crimp groove it got me thinking about why my buddy did it this way. The only thing I can think of is to reduce case capacity for the reduced target load he was loading but I don't necessarily see why that would help.

Is crimping on the driving band a common practice? If so, what is the reasoning? and is it something that would be beneficial for my 44MAG and 44SPL loads?

 

[ArchAngelCD]

Crimping at the driving band is a common practice for loading bullets without a crimp groove in REVOLVER ammo. Since a revolver will cause bullet pull under certain circumstances crimping slightly over the band will prevent the bullet from pulling. While it's better to use the correct bullets if that's what you have then you can safely use them and crimp there.

 

[Rule3]

You are mixing apples and oranges.

Driving band for semi auto usually for SWC bullets so they will feed up the feed ramp.

But for your revolvers you want to crimp in the cannelure (crimp groove) Seat the bullet to the top of the crimp groove (or just a hair under) and then crimp hard into groove even if it is a light target load.

 

[Bohica793]

I load 170gr Keith SWC (Lyman mold 358429) in both 38Spl and 357Magnum cases. In the 38, I can crimp in the crimp groove, but in the 357 cases, I have to crimp at the top of the first driving band in order to stay under max COL. Both are perfectly acceptable and widely used. Where you crimp depends on the load, the COL and the applications. Remember that when you seat the round deeper, you are increasing the pressures and must insure your powder charge is not too big. That way lies madness, pain and an expensive visit to your local medical provider.

 

[BLUEDOT37]

Taper or Roll

+1 what Angel & Bohica said. The 45ACP LSWC you mentioned is obviously for an auto & doesn't have a cannelure/crimping groove. If used in an auto/1911 you'd taper crimp it, on the driving band to the appropriate OAL. If you're going to shoot it in a revolver/625, either a hot load (+P) &/or in a light gun (325NG) you'd want to roll crimp it over the driving band's shoulder to avoid bullet jump due to recoil, in the adjacent cylinders.

Revolver bullets have cannelure/crimping grooves so you normally roll crimp it there, which sets the OAL. If it's a heavier/longer than normal for caliber bullet, & the OAL will be too long for your gun's cylinder, if you crimp it in the crimping groove, you can deep-seat it to the driving band's shoulder, like above, & roll crimp it, provided you have the space available with the powder/case used.

 

[max]

There was an article in one of the magazines last year or so about crimping over the band and the author reported better accuracy.

 

[Rule3]

Is crimping on the driving band a common practice? If so, what is the reasoning? and is it something that would be beneficial for my 44MAG and 44SPL loads?

For revolvers, NO.

 

[Irelander]

Hey thanks guys. I ignorantly overlooked the fact that all those years ago we were loading for autos and I am now loading for a revolver. Thanks for the knowledge.