[Farmboy]

A 3 point sling would work fine on a M14.

3 point slings/patrol slings hold the rifle horizontal across your torso, great for patroling. One downside to the 3 point sling is the part of the sling that runs along side the rifle can get in the way of the boltcatch etc.

2 point sling is your everyday sling and can hold the rifle in the same position as the 3 point if you have the right sling.

1 point is made for CQB, you will almost always have the weapon at the ready so anything more than a 1 point can get in the way. Think shorter shotguns, MP5's, carbines etc.

Your problem with your G&P, is the attachments probably won't work with the M14