I've got 4 m14s and stud mounted all of them- as far as height goes, get a friend with a ruler and have him measure the distance between the bottom of the forend and the top of the bench with you seated in your firing position- or measure the height of your sandbags - either way will do- the principle's the same- as far as the accuracy goes, don't sell these rifles short- with the PROPERLY DEVELOPED loads TUNED TO THE RIFLE, they will do moa or better - and put the "thing that goes up" up so the rifle locks into your shoulder( I do know the proper name for it, but most don't , hence) as far as mounting the stud goes, I used the front rivet on the sling swivel, drilled it out, and put in a t-nut and sling swivel stud, cut that off at the right height and epoxied the works in place