If you can turn a wrench and use an allen wrench, then you will be able to put together a rifle in your basement. Savage uses a barrel nut to set head spacing. Because of this barrel nut, it doesn't require a lathe to fit a barrel to bolt face like on a any other rifle other than Savage. You will need an action wrench, and a barrel nut wrench to achieve this. Then you pick any aftermarket stock that fits a Savage action and you have a custom rifle built by you. If you want to save money on the build, you purchase a Stevens action, sell the barrel, stock, recoil lug, and trigger. You in turn purchase an aftermarket Rifle Basix trigger group (heard directions are good for installation and instruction), .250" Recoil lug, and a barrel of your choosing in what ever caliber and twist rate and stock.
I put together a list of stuff one time for a guy. Depending on what you decide to go with for stock, ring base, rings, and scope... you'll come in around $1200-$1500. If you want a muzzle break then you can expect around $200 for purchase and installation.
As far as caliber. The 300WSM and 7SAUM are going to give you about equal barrel life. That will be determined by how heavy a bullet you use and how hard you push them. If you shoot conservative loads with heavy bullets, I would expect around 2000rds. If you use light bullets, heavy bullets, and push them at high pressure loads (max) you can expect around 1200-1500rds. I trashed a barrel in 300WSM pushing heavy bullets with max loads in about 1200rds. But in was a 308Win converted to WSM. It had about 2000rds down the tube already as a 308. The 7WSM is going to give about 1200 from what I've read. 300WM you can expect 1500-2500rds. If you take care of the barrel, it will last a while. It will depend on how hot you run the barrel, how often you clean the barrel, and again the loads you use.
