Is it an old style, meaning a pinned & recessed cylinder, or a new style (no pins, not recessed and a square cut extractor)?
Armorers are trained to check the 'timing' (called 'carry up' by S&W) in new style revolvers by inserting properly sized dummy rounds in the cylinder's charge holes. The extractors in new style revolvers are intended to be held in place by cases in the charge holes when the guns are being fired (instead of being held in place by a pair of pins, as in the older models).
The extractor ratchets are cut at the factory when dummy rounds are holding the extractor in the right position. That being the case, sometimes cycling the trigger without dummy rounds in the cylinder won't allow for the cylinder to be turned, or carried up, as it would be when dummy rounds are used to check carry up on an EMPTY gun.
My revolver armorer manual lists a simple series of steps armorers can use to check for carry up in EMPTY revolvers using properly sized DUMMY rounds.
The cylinder stop should engage the cylinder notches before the hammer falls in DA (DAO guns).
1. Slowly pull the trigger to the rear until the ball of the cylinder stop engages the stop notch on the cylinder. (Don't touch the cylinder to 'create drag' or do it too 'sloooooowly', just slowly & smoothly pull the trigger.)
2. The cylinder stop should engage the the cylinder stop notch before the hammer falls. This should occur with all charge holes to see if you have proper carry up.
3. Doesn't carry up double action (a problem condition) - the hammer falls before the cylinder stop engages the cylinder notch.
(In single action the cylinder stop should engage the cylinder's stop notches before the hammer reaches 'full cock' during movement.)
FWIW, I've been told that the tolerances being used on the new style guns can sometimes result in the cylinder stop engaging the cylinder at almost the same time as the hammer starts to fall, and that it's considered acceptable. I've always preferred a distinct 'space' between the cylinder stop locking in a stop notch and the hammer being released in DA/DAO, myself. (Doesn't mean anything other than I became used to experiencing it with older S&W revolvers which had pinned extractors.)
If this is a new S&W revolver you should consider calling the factory, since their lifetime warranty can check for potential problems and address them under warranty. If it's an older gun you can seek the advice of a licensed gunsmith (unless you know a factory trained armorer) to check your particular gun and determine whether it's within normal spec or requires repair at your expense.
I had a new style J-frame which had a couple of charge holes where the cylinder stop didn't consistently lock in the stop notches before the hammer fell when using doing the normal bench checks. Close, it seemed, almost seeming to occur simultaneously, and not something I really liked.
I asked for the help of a much more experienced revolver armorer (since I'm more experienced with semiauto pistols as an armorer) and used the next step up over-sized hand (measuring a couple of them I ordered from S&W). I found it still didn't quite bring the carry up in line, but that the next size up after that one was too tight (and I didn't want to file the frame).
I ended up cutting a new extractor (which requires a factory-made cutting arm tool) and using the original hand which came with the gun (as required for repair). The new extractor and the original hand now worked normally and provided for excellent carry up when checked with dummy rounds. Ditto for live-fire, too.
My point? An 'easy' fix which could have been done by the factory if I hadn't been trained as an armorer and hadn't had the right tool (and new part).
Rather than wonder about it, why not have it checked? It's often easier for someone trained to identify and correct problems to resolve an issue before someone else has 'tried to fix it', you know.
Just my thoughts.
There are much more experienced revolver armorers (and gunsmiths) who visit this forum who can give you the benefit of their greater experience, too.