Found a nice S&W 28-2 at the lgs yesterday on the way home from work.  Got it home and threw in some snap caps and started dry firing.  As I started cycling through double action trigger pulls, something didn't feel right in hand when the hammer fell.  It took me a little bit to realize what was going on, but the cylinder isn't locking up before the hammer falls all the time when the trigger is pulled double action.  I am able to stage the trigger just at the hammer's breaking point but the cylinder can still spin.  I think this means the revolver's action is out of time.

I've never formally checked timing on a smith revolver before, never had to.  So I found a youtube video that showed a method to check timing by thumbing the hammer back and making sure to hear/feel the cylinder lock up prior to the hammer for each cylinder.  The gun passes this check just fine, every time.  It only seems to not lock the cylinder when the trigger is pulled through double action.

Any thoughts?  My dad recently had a not so great experience with Smith & Wesson's gunsmith shop, so I would really rather not send the gun to them if I don't have to.  It took them 9+ months to get his gun back to him.  Unfortunately now as result of trying to figure out what was going on, I have several firing pin dimples between the recessed chamber faces.

It needs fixed.  Fast or slow, SA or DA, the cylinder stop needs to drop into all six slots before the hammer is released.  Inertial carry up (Rotation) usually makes this not noticeable in actual shooting.

Discussion:  https://www.thehighroad.org/index.php?threads/is-this-possible-with-a-s-w-revolver-timing-issue.330836/

Stop hand turning the cylinder and dropping the hammer with the cylinder half way between charge holes.  You will eventually either hit the edge of a charge hole and make extraction a mess or break the firing pin.

Might need a new hand and/or cylinder stop.

Start by cleaning the revolver thoroughly, especially under the ejector star.  Next, buy a replacement cylinder bolt spring and give that a try.  If that doesn't work, take it to a qualified gunsmith.

Right here.  Do NOT send it back to Smith and Wesson unless you want it worse.

I don't know what your options are but I can recommend Mr. Sokol. He did an excellent job for me and did it quickly when I sent him my grandfather's duty gun. He fixed the timing issue and gave it a duty grade tuneup, it's a great revolver now.

https://chestnutmountainsports.net/

I have heard Cylinder and Slide mentioned.   They've been around for a long time.

The timing issues with S&W revolvers, like late lock-up, are most often caused by a worn hand. S&W's timing depends on the width of the hand and with skill and experience, a hand can even be manipulated once to work again. Since the D/A sear is bringing the hammer back less than when the hammer is set to the S/A sear, it shows in D/A first.

The easiest fix is to get an oversized hand and a Jerry Kuhnhausen S&W revolver manual and fix it yourself. At that time it is also good to check the window for burs.

I've opened up a number of S&W revolvers and frequently found them in one of 2 conditions:

Bone dry with no trace of lube
Gunked up with only God knows what kind of crap was squirted/ poured/ troweled in there

As others have said start with a thorough cleaning and inspection.

I had that situation.  My hand was worn.  I measured mine and it was the largest size available for the K-frame.  I ended up slight peening the very edge of the star until it went into time. It doesn't take much. I was done with it in about 30 minutes

A new hand is preferable, but if yours is like mine and at the maximum size already this is all you can do.  The only other thing is to send it to a Gunsmith

They do great work, but they have a long waitlist.