The Remington UMC 5-in-1 blank was made for the motion picture industry specifically for B-Western cowboy movies. The cartridge contained enough black powder to make plenty of smoke for visual effects, but wasn't load enough to send the average movie horse into a tail spin.
The cartridges were designed to function in single-action cowboy revolvers chambered for .45 Colt, .44-40 (.44 WCF), and .38-40 (.38 WCF), and they worked just fine in lever action rifles chambered for .44-40 (.44 WCF), and .38-40 (.38 WCF).
But, the 5-in-1 blank wasn't the only cartridge used by a long shot. For long distance scenes or war movies a bit more powder was sometimes necessary. Bigger rifle cartridges like the 303 Brit, .45 Gov., and even the .50-70 were often found in the property master's stores.
About 1920 the Stembridge Gun rental company of Hollywood was founded by James Stembridge and Cecil B. DeMille to supply guns to the movie industry. Stembridge offered blanks with your choice of 1/4, 1/2, 3/4 or full loads with either black powder or flash powder; depending on the effect needed, and whether you were filming indoors or outdoors.
After many years of hiking and photographing Chatsworth's movie locations I've accumulated a nice collection of blank cartridges; a few of which you can see in the photo above.
And, I'm kinda like the little boy digging though a box of horse manure while saying, "There must be a pony in here somewhere." I recently purchased a metal detector 'cause I know there must be at least one old prop-gun buried out there somewhere.