Hi, MCH!
Welcome to the Board, and congratulations on buying a FINE rifle!
I have the regular M1895 .45-70 w/22" barrel. Your M1895 GG should kick about the same, considering the shorter barrel and muzzle gas vents.
The kick with factory M1873 level loads is not bad. Somewhat less than a comparable weight .30-06 with 150 or 180 grain factory loads. The M1873 "Trapdoor" Springfield level loads are 405 grain RN at about 1300 fps muzzle velocity. For extended bench or plinking sessions, even THAT can get fatigueing, so I switch to 300 grain RN lead reloads at about 1200 fps velocy. 138 grain Round ball reloads kick even less, at pistol-bullet velocities (800-1000 fps).
Given the versatility of .45-70 reloads, you can hunt most anything from mouse to moose with that rifle.
Have fun!
John