With the M1, you are pretty much looking at a 308 gun for better or worse. How far is LR to you? What sort of performance are you looking for? With a lot of work, the M1 can shoot MOA or better but that would be work above the steep price from the factory.
For a $2000 investment, you get factory bolt action performance. If you want a semi blaster with heritage, then go for it. Service matches shoot them to 600m so they are capable.
If you want a LR (1000yd plus) rifle that will shoot 1/2 MOA, I would look at building a bolt gun. You also have all the different cartridges to choose from.
Jerry