NAA Black Widow et. al.

[denjohnson]

Are mag & LR cylinders (other than Ranger & Sidewinder) interchangeable?

[pietro]

.

Only on a "magnum" size frame, and even then may need some minor fitting - why it's better to send the gun/cylinder to NAA Service for fitment/timing.

[Uncle_Lee]

You should have a third type. "Maybe"

[Rick_Jorgenson]

You should not switch cylinders from one gun to another.

Each cylinder is timed for "that" gun.  If you bought a "Convertible" model (NAA that has both cylinders included) those two cylinders are timed to that gun.

I hope this helps with your question