Personally, I have used many Douglas barrels, some Shilen, PackNor,Shaw,and Lilja..My personal favorite is Douglas air g. in #5 wt. 26 inches long..I have never had a bad shooter in a custom barrel..I would buy a blank and have a good smith chamber it and fit it to the action..Squaring the action would also be done..I have never handled a model 70 in 300 wsm to check the magazine length..you might have to seat bullets pretty deep in that case if the magazine is short..if you really want to go with 200 grain bullets, you might select a 1-9 twist rather than the traditional 1-10..all of mine are 1-10 and they shoot 200 grain bullets very well...
