First of all there is no .308 Win Mag. that I know of. You must have meant a .300 Win. Mag. or a .308 Winchester. They are two different recievers. One is a short action, the .308 Win, the other is a long action, .300 Win. Mag. Two totally different cartridges and recievers. Yes you can have a McMillan A-4 stock made by Mcmillan to fit the Remmy 700. You just have to be exact when ordering from them to get the correct stock made to fit your action. If you are going to go to a aftermarket 5 round detachable magazine, Mcmillan uses Badger Ordance bottom metal with detachable magazine only. when you order you will have to tell them what recoil lug you have, what bottom metal you are going to use (stock or aftermarket), what barrel you are going to use (again stock or the kind of aftermarket barrel you are using). The stock will have to be fitted, inleted, and bedded to make it right. McMillan can do this for you or your gunsmith, unless you know how to do this yourself. McMillan doesn't have rifle stocks sitting on the shelf to order and just ship. Each one they make is cast to fit your particular rifle. They will take up to 4 months from order to deliver your stock. They will require a minimum of a $200.00 deposit. I recomend that you research more or contact your local gunsmith before you buy. Bell & Carlson also make similar rifle stocks at a bit less price.