I find most if not all of my DA revolvers carry up better in DA than SA. I don't know the exact reason. I have a Model 10 that would carry up late on 5 out of 6 chambers even in fast SA, but times perfectly in very slow DA. I dropped in a DAO hammer and solved the problem....

Even though it was an older Model 17, I think maybe putting some spent .22's in the chambers might fix the carry up.

I found it's not always the new pin-less ratchet S&W's that need rounds in the chambers to align the ratchet. I have a few older S&W's that carry up better with brass in the chambers.

I am just more curious than anything, what everyone else's "standard" is for timing. I'm sure many people have been carrying and shooting S&W's for decades that would fail my "test" but pass my dealer's test with flying colors.......I'm just not comfortable with trusting momentum to spin the cylinder into lockup.

I'm also a huge fan of Ruger DA revolvers, which carry up much earlier than S&W's, so I may have a skewed perspective on proper timing. I like how Rugers lock up well before the hammer is fully back.