I have an Uberti repro of the 1885 High Wall in .45-70 and the same model in .38-55. They are both great shooters and extremely accurate. I first loaded both with H4198 and I tried 5744. The 38-55 likes the H4198 and the 45-70 favors the 5744. I load to original 45-70 velocity (1300 fps) useing 405 gr hard cast lead bullets.
Uberti 1885 High Wall fitted with Soule tang sight set, 27 gr. 5744, 405gr Laser cast bullet, Win LR primer, Lee factory crimp, OAL 2.550", fired from a bench rest = .04 X .22", 3 rounds @ 100 yds. (Everything went according to plan and Murphy was on vacation)