Well, in rebuilding my second 1006 into a 1066 I wanted to put in a 645 hammer because it has a half-cock notch. Why? Because it makes the double-action stroke shorter and reminds me of my Sig P-220.

I was warned that the roll over of the 2nd Gen S&W's was not as good as the 3rd gens (which the 1006 and 1066 are). I was given three sears to attempt to compensate for it: #2, #4, and #6.

The #4 is what the pistol had in it and the DA with the new hammer was HEAVY.
The #6 actually had the best DA and SA pulls BUT the break was HARD.
The #2 was the best compromise but the rollover was still noticeable.

I pulled it out and went back to the original hammer. Interestingly, I also tried my four different sears. The best and worst overall triggers went to the #4's (one was really nice and the other terrible catch on break).

Weird huh?