Joe: I had a 45-70 BC excellent rifle but if your hunting will keep you in a 100 yard target why not look into the Handi 45-70 I think they are 22" barrel and you will have a choice of iron sight or scope. I loaded the BC using the 405 grain bullet with black powder loads also tried the 525 postal lead bullet with 65 grains of black but the light rifle will shatter your teeth with heavy lead bullets.
I made a bad choice when I purcahsed the 45-70 I should of went with the 38-55 I am not a fan for recoil