You want an inch pound 1/4" drive torque wrench. Most automotive stores (NAPA) will carry these. Also listed in Brownell's. Expect to pay about $200 for one worth having. Snap-On is excellent.

About the most torque you are going to need for stock screws is 65 inch pounds - recommended for the H-S Precision rifle stocks with the aluminum bedding block. Normal wood and synthetic stocks will run in the 30 to 45 inch pound range. With a muzzleloader, this is an especially nice little tool to have around when youneed to remove the stock to do a thorough cleaning job. Can remove and re-install the stock without loss of zero (at least in theory).