Use a square-handled screwdriver & put some torque onto it to tighten. Use a correctly-fitted wrench on the square shank of the screw-driver. If your butt-stock is loose, your rifle won't group as well as it can. Also, after you have correctly cut to shape a piece of paper to use as a paper shim around the outside of the wood that fits inside the butt socket, you soak it in white glue in order to tighten up the fit. I've also used wax paper & even black tar paper when one was really loose & no spares were available. Also, make sure the end of the butt does not bottom on the face of the inner butt-socket face.
You can make up spacer washers in the event your stock bolt is too long. Don't go cutting original stock bolts. By using a washer/spacer, you can reduce the amount your bolt face protrudes from the wrist socket, BUT, you cannot lengthen a shortened bolt for the next project!