If the cylinder of the 1860 Army revolver is accidentally rotated past the ram with the ball only finger tight in the chamber, you cannot rotate the cylinder in either direction in order to remove the ball so you can reposition the cylinder. When the cylinder is accidentally locked in that position, you must disassemble the pistol and remove the barrel in order to reposition the cylinder so you can seat the ball with the ram. The '51 Navy revolver has a stop on the left side of the barrel frame that will not allow the cylinder to accidentally rotate past the ram. All revolvers I have seen, except the 1860 Army, has that feature.
I can put 30 gr.of black powder in the Colt Navy and Army 44 revolvers but I cannot place a Wonder Wad on the powder to prevent a chain fire. If I reduce the load to 25 gr. I can put a Wonder Wad on top of the powder and still seat the balls flush with the cylinder. If I place a Wonder Wad on top of the powder, I can carry the pistol unloaded and seat the balls later. If I use only 25 gr. of powder with a Wonder Wad, the ball will drop three feet in 50 yards. A 30 gr. load without a Wonder Wad will carry the ball 75 yards with only about rwo feet bullet drop.