iamcanadianeh
CGN Regular
- Location
- Vancouver Island
Try some cast lead as well. A few of my guns group around a half inch tighter when shooting cast vs jacketed. You'll want to play with the loads a little since tighter groups with cast rounds relies to some extent on having enough of a POP to obturate the bullets out for a nice fit in the grooves.
Sorry I can't help out with any special cast bullet load data. I just know that the couple of times I've loaded up some cast that it shot noticeabley tighter groups with the cast vs jacketed. And as with any of this you'll want to try out some various powder amounts to find the one that works for YOUR gun. It's all related to matching the bullet velocity to the twist rate and in the case of cast bullets to using the one that forces the bullet to expand out for a superior fit to the rifling.
With the rimless handgun calibers you want to crimp in only enough to remove the flare. The rounds headspace off the case mouth so you want to leave them out where they'll rest solidly on the rim of the chamber. So the best crimp for these is either no crimp, but no flare, or at most a slight inward crimp that is all but unnoticeable. Most cast bullets come with a cannelure groove. But you don't want to do more than to crimp the case mouth into this groove by the slightest amount. If you can't run a finger nail over the lip of the casing and have it catch solidly then you went too far with the crimp or the bullet is quite oversize. Either way you want to do a "plunk test" at that point to see if the round chambers correctly and that the lip of the case is still able to seat solidly on the chamber lip. The cheap person's way of doing a plunk test is to field strip the gun and use the barrel itself. The rounds should fall in loosely and stop on the lip with a solid feel and sound. And when tipped up they should fall out loosely into your palm with no hesitation that suggests that the crimped lip of the casing was wedges into the chamber rim.
Folks that are flush or fairly OCD get an ammo gauge to use so they don't need to take the gun apart for this plunk test. And REALLY flush or overly OCD folks will even have a smith do a chamber casting and have a matching ammo gauge made up that is an exact match for their pride and joy guns. Or someone like me will use their own machine shop to do the same thing.... when I finally get that shipment of "round tuits"....
Very helpful post, thank you!
