Sounds kind of long, all right.
Have you checked the chamber length? Some of the Italian guns came across with chambers longer than 2.1" even though marked .45-70. You might have a .45-90 in disguise.
But you most likely just have a .45-70 with long throat.
I see a lot of BPCR shooters loading grease grooves out of the brass to get the bullet into the rifling, or using tapered bullets to stick grease grooves up into the bore to leave more powder space.
I don't think it matters for target shooting, you can load long and keep your ammo with exposed grease grooves clean.
And for hunting, a jump to the rifling probably doesn't matter much at iron sight hunting ranges.
My Browning BPCR .40-65 only lets me load the front band out of the case mouth, no grease grooves showing.
My Winchester rebored to .38-55 has such a long throat I cannot get up to the rifling at all.