With subsonic loads I wold look instead to head shots. I have several loads that would be perfect for that kind of shooting. I prefer headshots to neck shots, as the neck depends totally on hitting the spine. While a deers brain is no big target itself, it does offer some sure signe of where it is. A seer quartering toward, put the shot between the near side eye and ear. Quartering away, the reverse of that shot. going dead away, the union of the skull and the neck, facing dead on, right through the juction of the snout and the skull, commonly called between the eyes, but just a tad low of the eyes horizontal centerline. It is a small target, a miss will generally be a clean miss and the 44 is certainly capable of the required accuracy, and it can be made quite. My neighbors don't complain about a load using 11.5 grians of Blue Dot which makes 1275 fps. Down in a hollow, my neighbors generally don't even know I've shot.
I normally only shoot for the lungs, things happen quickly in the woods, head shots require enough motionless time for very solid target aquisition and sight alignment, even a scope requires time to settle on a 1" diameter target.
All that said, at 25 yards and less, lung shots with heavy bullets at pistol velocities will perform quite well too. I've taken a lot of deer at that range.