Spinning cylinder question

No, it isn't terribly likely you did any damage at all to that Ruger.

If the cylinder still opens and closes correctly, the seam where the crane closes against the frame still looks "tight", and nothing binds as you cycle it, go shoot -- it's fine.

Short of using an alignment range rod to check the chamber-bore alignment, there's not much to be checked other then timing.

Timing on modern guns like the Ruger's is fairly simple. Check timing on all chambers.

As you slowly cock the hammer the cylinder locking bolt should drop into the frame and unlock the cylinder before the cylinder begins to rotate.

The bolt should drop back onto the cylinder shortly after it starts to rotate and should "ride" the cylinder for most of it's rotation.
This will leave a line on the cylinder.

The cylinder locking bolt should drop into the cylinder locking notch and lock the cylinder before or just as the hammer reaches full cock.

The cylinder must have some looseness when the gun is cocked, whether the trigger is held back or not.
This allows the bullet passing from the chamber to the bore to force the cylinder into alignment with the bore.

NOTE: checking for how tight the cylinder is with the trigger held back is a valid test ONLY for the old style Colt action as used on the Python, Detective Special, etc. All modern revolvers are specifically built to allow some looseness when the gun fires. Some may seem to be tight but enough backlash is built into the action to allow the cylinder to move slightly when fired.

I recently checked out a Mod. 28 5". I was not too pretty although without damage. It just was matte- finish like. The gun had no cylinder play at all, with the trigger held. Seemed strange after all the rounds that probably were fired. I seem to recall a 28-1 #. Interesting that the design allows for movement upon firing.

Wow 357 posts had no idea

Like others said ...you're probably fine / just check the timing on it ....and go have some fun with it !