love the 45-70 cartridge... I have 4 guns chambered in it... a 14" Contender pistol, a newer Remington double rifle, a custom old Martini single shot safari rifle, & a newer stainless ported guide gun... I greatly enjoy shooting them all... the Contender is by far the lighytest weight, however it has a "hunter" barrel, which is ported, & takes some of the sting out of it, but it's defintely a boomer... the Martini probably hurts the most, because the straighter stock style directs more recoil directly into the shooters shoulder, coupled with a light weight octogon barrel... the double rifle, while being pretty light for a double, still has more weight there than some of these other guns... my newer guide gun has a short ported barrel, which I didn't think I'd like, but I'm doing some very heavy reloads ( African safari hot loads...
) for the Guide Gun... these loads are at least as hot as the 450 Marlin, & some are hotter... I fired some test loads in the gun with 3 purposes in mind, make sure the big old bullets would cycle through the gun, check cases for pressure signs, & see if I could handle shooting them in the 1st place... I was actually pleasently suprised... I found them pretty easy to shoot... between the ported barrel, the factory recoil pad, covered with a nice leather butt cuff, the gun was pleasent to shoot, even with the hottest of loads...
so without arguing 450 Marlin, vrs the 45-70... if the gun kicks too much, & he wants to keep it, look into having the barrel magna ported or equivelent... maybe add a better more obsorbent recoil pad...
45-70 puts a big
on my face... always has, ever since I 1st touched off the trigger on my 1st one 20 or more years ago...