Obviously, I am enamored with the .308 Winchester. I'm not a varmint hunter but I am assuming the barrel is of the heavy variety. Since you are hunting over fields that are open, why not use a ground blind and then the weight of the gun isn't so significant anyway? If you were going to be trekking into the back woods carrying the gun long distances, I could see the problem of the weight but if it were me, I'd hunt these open fields from the blind and use some sticks to rest on and take advantage of the familiarity I already had with the rifle as well as its' accuracy for the long shots you will likely encounter. Beside these considerations, what is the availability of ammunition for the WSM and the difference in cost, etc.? You're probably going to have this rifle for a long time to come, so these are valid considerations to mull over and, as many have stated, never rid yourself of an accurate rifle.
