I have put together 3 on the 7-300 win lately,,,
for the issues of case forming ,trimming, neck turning and finding cases,
I would stay with a standard 7mm mag for any of the 168gr and smaller bullets, and a 1-9 twist, if I wanted something to sling the 190 bullets I would step up to a bigger case, stw or 26 nosler necked up,,,
I used a lilja , bartlein and brux barrel ,,25 to 27in long,,,,
realistically there is not an animal in the world that will know what case fired the bullet that took its life, but being able to buy 7mm mag brass and load and shoot, muchless finding factory ammo about anywhere,
has sold me to stay with the factory 7 mag, happen to have 5 of them in the rack, also have a 7stw that I barreled with a lothar walther barrel, it really shoots the 180 berger hybyrds,,