Originally Posted by Hawg
No, that's just what Ruger says. I know they work from one new model to the next.
No, that's not just what Ruger says. Any competent revolver-smith will tell you that too.
The cylinder/hand/lock combo is timed at the factory to provide the proper chamber indexing. If they're not installed and timed properly you might run into lock-up problems or chambers that are misaligned to the barrel.
As well-built that the Ruger revolvers are, they're production tolerances are not tight enough that parts are 100% drop-in interchangeable between guns.
Check your cylinder/chamber alignment if you've fitted a new cylinder.
Yes, the New and Old model SS cylinders are dimensionally the same and are interchangable. The key differences between the Old and New Models are in the internal lockwork
Most cylinder swaps will most likely fit and function, but the key is will they function properly and accurately. The dual-cylinder sets are matched up & timed at the factory and are marked with the last 3 digits of the frames serial number.