I have wonder about the rifle carried by Paul Newman's character John Russel in the film HOMBRE. It appears to be a Winchester "66 Yellow Boy, with a half magazine, but it looked like it used 45-70 cartridges? That is what the character carried in the cartridge belt?
Maybe just for the "looks" effect? I read a while back on another board that the Mares Leg that Steve McQueen carried in "Wanted, Dead or Alive" was a Win '92 that would have been a pistol caliber, but his belt was full of 45-70's too.
My opinion is that most in Hollywierd don't have a clue when it comes to guns, and/or think the rest of us don't either. Good news tho, recently some of the directors have been hiring folks that actually have an idea what is period correct, and what goes together. Ever notice in some of the old Civil War era westerns the guys are using Colt SAA's and Winchester 92's and 94's?