When I worked in a muzzle loading shop, we’d see 2 or 3 (minimum) 44 calibre Colt style pistols per week where the brass frame was either worn out or damaged. The brass framed 51 navy’s in 36 cal. held up reasonably well, and the brass framed Remington 58’s held up very well. The bottom line is that if you shoot much the steel frame will last longer.
It was our policy in the store not to carry brass framed Colt style pistols in 44 cal. We also did not carry 51 Navy's in anything but 36 cal.