I note that many people who check in with the message boards for Western movies and tv shows, particularly the more accurate ones, seem to know quite a bit about frontier-era firearms. (See discussions of Josh Randall's "Mare's Laig" elsewhere on this board.) I understand that the Winchester '73 rifle--the "Gun That Won the West"--was in .44-40 caliber, and that it was popular with cowboys because it could fire both .44-40 cartridges but also .44 pistol cartridges, eliminating the need to buy and carry two different types of ammunition. Does anyone know if the .45-70 round, which the Winchester '76 was chambered for, could also fire .45-caliber pistol ammo? Or did that extra "-70" make it a poor fit? Thanks, range riders!
The whole use of Randall's "Mare's Leg" weapon creates a whole bunch of problems concerning period accuracy. I have always been led to understand the series took place in the 1870s, and if that is the case, that would eliminate the Winchester models 1886, 1892, and the 1894. It would then require the "Mare's Leg" to be either a Model 1873 or 1876.
Why is this a problem? Because of the different calibers used by the different models. If it was a Model 1873, it pretty much limits it to using eith the .44-40, the .38-40, or the .32-20 cartridges. The Model 1873 was never designed for higer powered rifle cartridges. If it was a Model 1876, it would have been chambered for the following rifle cartridges: the .45-75 WCF, the .40-60, the .45-60 and the .50-95. The Model 1876 was not chambered for the very popular and very powerful 45-70 Goverment of the day. The Model 1886 was the first Winchester chambered for the 45-70, but that puts it out of the 1870s era when the series was supposed to take place. The Model 1894 was the first chambered for the 30-30 cartridge, and also puts it out of the 1870s era of the series.
If one looks carefully at the cartridges in Randall's cartridge belt, they are obviously not the less powerful pistol cartridges of the Model 1873. I am unable to be sure what caliber they are, but they do look like they could be 30-30, 38-55, or 45-70. I recently watched one episode where Randall bought a box of 45-70 ammunition which one would suppose was intended for his "Mare's Leg." Neither 30-30, 38-55, nor 45-70 cartridges would have been used for any of the 1870s Model Winchesters, and that is what makes the whole "Mare's Leg" use a problem in being "period correct."
In response to your questions about interchanging cartridge calibers, they really are not interchangeable. The 45-70 uses .458 bullets while the .45 Long Colt uses .452 jacketed bullets and .454 lead bullets. The .45 Long Colt is not designed to be used in a 45-70 chamber.
So, how is that for making a mess concerning the use of the "Mare's Leg"? If Randall was using the early pistol bullets of the Model 1873 or the rifle bullets of the Model 1876, then things would work out just fine. However, the bullets he carries in his cartridge belt simply are not for either the 1873 or 1876 Winchester Models.
I hope that gives you some idea of Winchester models and calibers even if it seems to muddy the waters.
Close inspection of the receiver of the "Mare's Laig" shows clearly that it's a cut-down model 1894 Winchester, originally chambered in .30-30 caliber. Also,I have heard it mentioned recently in watching reruns of the show that it used .30-30 ammo(some remark as to what damage a .30-30 would do to the potential human target). That doesn't mean that in other episodes other references weren't made. This is one of several inaccuracies and incongruities present at different times in the series. It just goes to show that historical accuracy wasn't a major consideration in these early TV Westerns- entertainment was.
The other two posts are very helpful. My own observations of Josh Randall's ammo belt tell me that the cartridges in it seem to match the .45-70's I have for my own rifle. On the other hand, the number of rapid-fire shots I seem to recall Randall making would make his prop-gun a pistol-ammo weapon, at least with respect to the blanks he fires on the set (if any actual shots/blanks are even fired during a scene). A sawed-off rifle of the size of Randall's could only hold 3 or 4 .45-70 cartridges, including the one in the chamber; seems to me he's routinely cranked-off more than four at a time.
Another point about the .45-70 round: I've owned two .45-70 rifles, and believe me - the .45-70 is no handgun round! In a full-size rifle fired from the shoulder, it's more or less on a par with firing a 12-gauge shotgun slug; it packs a wallop on the shooter. But in a sawed-off rifle, fired rapid-fire in a crouch from the hip - no way. The first shot would yank the shooter's grip loose; successive rapid-fire shots, in my opinion, would be all but impossible. In short, it's a Hollywood concoction - a fantasy gun - firing light-load .44s, but with .45-70s in the belt loops.