they have been around since the early-mid 80's I think was when Remington legitimized it. my dad used one for several years before he passed in 1988.
RR

I believe I read somewhere that there is yet another new cartridge under development. If I remember correctly it will be called the 45-70. It may well be just another flash-in-the-pan, but maybe it will catch on.

Remember, you heard it here first!

Just looked into the 45-70 thing. Man, with a cartridge like that I bet you could kill just about every buffalo in north america................oh wait........