I have five 1858 Remingtons and three are brass, one I've had for over 30 years and there's no stretch on any of them, but then again, I don't shoot them every day. Most of my shooting is done with my steel frames, and then I can use my conversion cylinder. I do take and use my brass frame 1858 Remington Bison when I go hog and deer hunting, along with a rifle, but sometimes I don't feel like lugging a rifle around so I'll strap on my Bison and use it. I've put lots of meat on the table with my brass frame Bison. What I will do if I don't use it after the season is over, I'll take the cylinder and put it in a steel frame and shoot holes in something.
I hunt two seasons, Firearms and Muzzleloaders, and I'll carry the Bison with both, or I'll carry a steel frame with the .45 cylinder. When I hunt firearms, I'll use either my .30-30 Winchester or my Mosin-Nagant 91-30 and muzzleloading I'll either use my Kentucky or Hawken, both are flintlocks.
If your's get to bad to shoot, buy a steel frame of the same brand, such as Pietta, Uberti, or whatever, that way you have a spare cylinder, cylinder pin, plunger, springs, hammer, grips, barrel, hand, stop, screws, and nipples. Did I leave anything out?