Proper cast bullet size for 1873 Winchester/Uberti .357 Magnum?

[Brazos_Jack]

Uberti/Cimarron lists the groove diameter as .355". If that is so, it would seem that you would not want to size cast bullets any larger than .357", instead of the .358" to .359" that we think of for .357 revolvers.

Have any of you with 1873 Uberti's slugged your bores? If so, what did it measure?

Have any of you tried sizing bullets to .356" or .357" for these rifles? If so, what was the resulting accuracy?

[DougGuy]

Size to fit the throat.

[Brazos_Jack]

Size to fit the throat.

Since this is a lever action rifle, not a revolver, I know of no convenient way to measure the throat. I do not have the facility or knowledge to do a chamber cast.

Has anyone done a chamber cast of an 1873 uberti and determined the chamber throat diameter?

[Wind]

Hey there Brazos Jack -- Doing a chamber cast in a '73 can be problematic!! The magazine cutoff and cartridge feeding are related to the length of the lifter. The cartridge just fits this dimension shown in red...

178550

If your chamber cast is any longer than the overall cartridge by including any throat/barrel area, the casting won't come out of the rifle. A bore slug might serve your needs for bore diameter questions much better.

I shot tens of thousands Laser-Cast 158 and 180 grain .358" bullets through the rifle pictured with fine accuracy.

Hope this helps. Best regards. Wind

[ReloaderFred]

Most of the SASS shooters I know who are using 73's are shooting .358" diameter bullets, and most report no leading.

Hope this helps.

Fred

[Brazos_Jack]

Pending getting some actual measurements, I'm going to assume that my rifle has a throat that is at least .358" and has a .355" groove diameter (maybe they use 9mm Parabellum barrel making equipment?}.

I'll size .358" but keep hardness moderately low (11-15 bhn) and completely avoid jacketed bullets.