Thank you 2006 for your reply. I'm also a Marlin junkie with a family of 18 Marlins new and old. If I'm not mistaken, there is a warning on45-70 LE ammo boxes not to use this ammo in older rifles and I believe they state 1974 or older. I also have a 1951 336 30-30 that loves LE ammo and last year it took a dandy buck at 187 yard and a doe at 103 yds. One shot and down they went. I agree that the heavier loads should only be fired out of a newer levergun and not the older ones.