What bullet weight do you guys use in your .300 mag. I recently picked up a model 70 in .300 WSM to play with. My initial thought was that if your going to shoot a .300 mag might as well shoot at least a 180gr bullet. Now I'm thinking that with a TTSX a 168gr might be just as good if not better. Would a 180gr TTSX have anything on a 168gr TTSX.
Keep in mind that this rifle will not be used for deer and only an alternate to my Whelen for moose and possibly elk.
My Son In Law has recently had a custom 300 WSM made up and the test results were from loads made up by the custom builder, using 180gr Barnes TSX. I'm guessing the choice of bullet was his. He got the 'receipe' for me and I've just cranked out a big batch of ammo for him duplicating their load specs. We're heading out that way shortly so I'll deliver the supply to him then.
In my change over to Barnes, in my 30-06 Husqvarna Light Weight with a 1:12 twist, I've pretty well settled on the 150gr TTSX although

the 130gr TTSX isn't totally out of the question yet.
In my 308 NM Schultz & Larsen, 1:10 twist, I haven't yet decided whether I'll go with the 168gr TTSX or the 180gr TTSX. Quite probably the 180's.
In addition, where possible I've gone with TTSX over TSX as they have a larger hollow point and therefore
should open up quicker or with meeting less resistance. And if they do, fragmentation shouldn't be a concern as they supposedly hold together well.
Back to your initial question and while I don't have any field experience with Barnes on game,

yet, I would guess either of your choices would do well. My choice would be the 180's.