You fellers are underestimating the 4 and 6 inch revolvers at 70 yards. The gun will do it if the shooter is up to the task.
Since all my revolvers have 4 inch barrels or less, S&W M25-5, M27, M586, M66, M15, M12, M36, M940, I would say, 6" barrel should be your choice.
Granted, you can do 70 yards. I shoot 100 yards with my Model 15 at gallon and 2-pint bottles. I can still hit them.
However, a longer barrel gives a better sight picture and hence, if you are shooting at animals (pests), the chances of getting a good hit improve with that mere two inches.
Also, the bulkiest parts of a revolver are the cylinder and stocks. Barrel length actually does not factor in much in terms of ability to carry a gun, even in a vehicle. A hide-ride or cross-draw holster will take care of that problem, which again, isn't really a problem.
Yep, I would go with a 6 inch barrel.
The Doc is out now.
(and this was my 500th post here)