It's been repeated so often ... it's accepted as truth ... "revolvers don't fail" or somesuch silliness. While most top shelf manufacturers put out sturdy machines ... they are still only hunks of steel, plastic, wood, etc., machined to work together as a system. Any machine can fail. For any number of reasons.
My 625 runs like a top. When ever'thing is dialed in. I learned through a year of shooting several things.
Revolvers can and do have malf's. Rounds without a heavy enough crimp will make a moonclip difficult to run all the way home. Mixed brass can cause problems. Even with a wheelgun, brass brand makes a difference. Some manufacturers have very slight dimensional differences ... enough that combined with a very slightly bent moonclip ... will bind the cylinder tight.
Tam over at View from the Porch, has a few enlightening things to say about revolvers also.
