.44 Special factory ammo has always been loaded to a very mild level, less than 15,500 psi. There may be some boutique loader that makes stout stuff but you won't be encountering much of it in stores. If it was made by Winchester, Federal, Speer or Remington, it will be gentle on your gun.

If you want something even more low pressure than standard stuff, W-W makes a cowboy action shooting loading that is even lower pressure and velocity than standard stuff. Winchester's cowboy load uses a 240 grain lead bullet that looks like a round nose with the round tip cut off to make it flat. My guess is these might shoot to a different point of impact than the traditional 246 grain W-W and R-P loads do, but the 200 grain loadings in .44 Special shoot lower, too, so... I bought a few boxes of it a while ago but haven't shot any of it yet.

Anything made by the big 4 will be plenty safe in any .44 Special revolver ever made by Colt or Smith & Wesson that is in good mechanical condition, no matter how old the gun is. The .44 Specials made by them were always top-of-the line designs.