Hint: the holes for the nipples in a Remington enter the chamber at an angle, they are not in a straight line with the chamber.
I think that might be the problem.
The Colt nipples enter the rear of the cylinder straight on, parallel with the bore.
Remington pistols nipples are tilted slightly towards the axis for the cylinder pin. If a person tries to screw them in parallel with the bore, they won't start or if they do, they will rapidly bind up.
Rethreading the nipple hole in the cylinder is about the very last thing I would even dream of, let alone, try to do.
Lets look at the problem.
The nipple was screwed in at one time.
There isn't much that can be done to mess up the threads in the cylinder without really trying (like forcing a cross threaded nipple into the hole).
So... if the hole wasn't frinkled up by someone forcing a hardened nipple into it, there is no reason to fix it.
Even if the hole was damaged by forcing the nipple into it at the wrong angle, most likely the threads weren't damaged too badly so screwing the nipple in correctly will probably fix it.