I would ask myself how many rounds a year am I realistically going to put through this gun. As far as barrel life I antincipate 1500 to 2000 rounds before I will start to get concerned about accuracy of my 7MM STW. Now that I have my load developed i doubt that I will shoot more than 100 rounds a year with it.
That being said it will take me over 15 years to shoot out my barrel if it is shot out at 1500 rounds and that accuracy will only be reduced (in My opinion for target and not minute of deer). The reality of my hunting is that my shots are less than three hundred yards. After ten years I can re barrel to same caliber with a custom barrel or re chamber and fill like I got a new gun ( which I will rightly deserve LOL). Also if you are not shooting max or over on the loads that will help on barrel life.
What I am getting at is unless you are planning on shooting 100 plus rounds a week through this gun and need the accuracy of a match rifle to hunt buy what you want and worry about what your children or grandchildren will do with your deer slayer gun.
By the way I would chose the 7MM STW over the 300 RUM any day but I'm biased.
Founding member of the 7MM STW Club
Member Texas Cull Hunters Association