There are other sorts of 45-70 rifles. The original was the Springfield "trapdoor" which is an antique but is also made in various replicas. The 45-70 can also be found in modern bolt action rifles.
The fact that my rifle is stamped with "JM" is important. In 2007, Remington bought Marlin, moved the factory location, and nothing good came of it. Remington went bankrupt, but in 2020 Ruger purchased Marlin and is now resuming production of their leverguns and people have hope that Marlin quality will be restored.
My "JM" stamp indicates that my rifle was produced before the Remington disaster, and my rifle certainly shows every evidence of being a quality item. JM stands for John Marlin. Remington manufactured rifles are stamped "REM".
I have another Marlin rifle, an 1894 "Cowboy limited" also with an octogonal barrel, and also stamped "JM". This rifle is chambered in .357 and has a 20 inch barrel. It will fire .357 or .38.
At one time these wre on the rack in gun shops. Now they are highly sought after.
Tom's Computer Info / tom@mmto.org