45 Colt/454 Casull Dies

[RoyceP]

Originally Posted by Unclenick

Colt changed the rifling groove diameter to 0.451" well before that. Mike Venturino says he's seen a 1922 Colt factory specification sheet showing the smaller diameter. It suggests that when they started making 1911s for the government, they decided they didn't want to maintain gun drills and reamers and rifling cutters for both sizes. But revolver chamber throats took a lot longer to change. At first, they would just be avoiding obsoleting old ammunition. Later, maybe they were keeping old bullet molds alive. I don't know. I actually can't find any hard dates for the cylinder throats mentioned anywhere, so my comment may have been misplaced. I know Ruger doesn't undersize throats, but I don't really know when other makers may have given the practice up.

I own only two SAA's, one made in 1980 and one made in 1885 with neither being 45 Colt caliber. I have owned Ruger SAA's in 45 Colt and still own many S&W's in that caliber. Never measured a throat - I only shoot for accuracy. I selected what works the best. If I buy factory ammo it is only to get the brass. I have not bought factory 45 Colt ammo in at least 35 years.

I only know what I know because I started reloading around 1985 and at the time Sierra and Hornady offered 45 Colt components with bullets sized to .454". It was maybe 10 years later before I ever saw any bullets sized to smaller dimensions for 45 Colt caliber.

[Unclenick]

In general, if a lead revolver bullet is too loose in a chamber throat, it shoots poorly. An extra-tight bore does not have nearly as deleterious an effect on accuracy, though it will make it more important than usual to have a perfectly symmetrical forcing cone and for it's chambers to line up accurately with the bore. So we have a chicken and egg situation wherein oversized throats may cause mold makers and sizing die makers to favor those wide throats to try to get as much accuracy as they can from the wide-throat/narrow-bore arrangement, while the wide bullets make the manufacturers stick to wide throats. How to break the cycle?