I swapped out the original MIM trigger for a new, old stock .400 smooth faced, satin, stainless steel trigger. I've done this many times, so I know I've put everything back together properly. Single action pull is smooth as butter but double action has a slight stick to it at the very beginning of the trigger pull cycle. I first thought it may be a burr on the hand, where it engages the cylinder cog, advancing the cylinder to the next chamber. I smoothed and polished the hand edges but the problem remains.
Any suggestions appreciated.