What you describe can be typical of a gun set up for PPC competition. Could be the result of too much polishing,wear, or someone getting into the action and hitting the wrong spots. If you intend to shoot it double action only dont worry about it or set it up for DAO and bob the hammer. 99% of PPC shooters shoot double action only today at all distances.
If you know someone that is familiar with the actions you can prob. stone the single action sear and get it back to safe release condition. Safe trigger weight is normally considered 2.5 lbs.
As long as timing and ranging good and no other defective gunsmithing in evidence prob good to go
Hope this helps a little