What can I do to help my new M1A standard to shoot better than 4to5 inch groups

[CINDERS]

What may be a thing to do is to have it checked over by a competent gunsmith familiar with these weapons, you do not explain fully how you are shooting is it benched off a rest, dead sled, prone with a sling, standing unsupported there may be an issue with the crown of the rifle pretty tall order for the chaps here to get you onto the right path have it checked out I mean the barrel may be shot out, bedding not up to par anyway these are just a few things for you to consider. Have you checked all the screws on the mounting bracket my friend has had scopes go south on him 3 times 1 for no reason the elevation turret just spun round and round. You could do the walk around a couple of times on a target to see if the scope is tracking correctly.
Walk around start at one point move using the same point of aim for each shot fire one shot dial in 6" Rt fire 6" down fire 6" left fire 6" up to your original start point will show if the scope is not the issue as it should print right on the first bullet hole you started with hope that helps you a bit.
Oh yes the 2 scopes that were destroyed on my friends rifle were Leupold's 1-4 power on his 460 Weatherby Mag