I've owned and used 45/70's for about 40 years , everything from rolling blocks to single shot's , levers and bolt guns . It's a very popular cartridge in Canada . The fact that it was formerly an American military cartridge has nothing to do with it's becoming a hunting staple up here . It didn't really become popular until the introduction of the Marlin 1895 , there's always been a few 1886 Winchesters and Rolling Blocks kicking around , but in smaller numbers . The last Trap Door I saw was mine , and that was a long time ago . Long story short , in Canada at least , the 45/70 is actually a fairly recent cartridge to see common use . In all my years using them , different loading levels have never been an issue , I've never heard of anyone else capping off a level three load in a Trap Door either . The reason it's carried by so many people , myself included , is because it's a very effective hunting cartridge within it's range limits , nostalgia doesn't enter into it .
After using it for as long as I have , on a lot of game , up to Moose and big Bears , I've found that hot rodding it doesn't really make that much difference in the field . I've shot Moose with factory Remington 405 gr's at about 1350 fps ( yes I know it doesn't meet UK legislation ) and 405 gr hard cast gas checks at about 1850 . The reactions were all pretty much the same , after the shot , they all went about 10 yards and fell over . I've settled on 405 gr hard cast gas checks at about 1600 fps for everything for the last number of years . It is an absolutely reliable killer on anything I'll run into and doesn't destroy a lot of edible meat in the process .
I currently have a Marlin 1895 Guide Gun , ridiculously accurate for a short barreled big bore . They're not for everyone , but for anything we have , and I do mean anything , inside of 200 yards , you won't go wrong . Stalker308 took my last 1895 home with him a few years back . He used it to take a very nice Black Bear out here . He used a Hornady 325 gr leverevolution Flex Tip on it . The bear dropped instantly at the shot and never moved , that is not the case with most rounds . He was impressed enough with it that I gave it to him ( it was the right thing to do lol ) You should drop him a PM , he knows what he's doing .
The 45/70 is like two other great American designed rounds , the 308 and the 30/06 , efficient and effective . I apologise for the long post , but I'm a longtime fan of the 45/70 , it's still used because it works , and probably still will long after I go for a dirt nap . I wouldn't be without one .
AB