The DA trigger pull on those guns is not light, but shouldn't be that much.
First, try the pull with the gun open. If the pull is less, then the cylinder is binding somewhere. Look at binding on the cylinder arbor.
If it is the same, then the trouble is in the frame. Several things can be wrong in either case. Did you replace the mainspring (hammer spring)? If so, did you get it the right length? Most springs available today are made oversize so they can be fitted to more than one gun, but if left long they can hit the frame when they bend, increasing trigger pull. You also want to make sure it is not too strong.
Another thing to look at is whether in working on the gun you may have pinched the frame so the hammer or trigger is binding.
Jim
