I made, Kydex Cheek Risers for my Tikka's, to obtain good, "Cheek Weld's" for longer distance shooting and put, Elay Precision, Trigger Springs in them, then set, the trigger Pulls for, a Crisp, 1.5 Pounds. I carry 3 rounds, in the Magazine ( Empty Chamber, til' ready to, shoot an animal ).
Your probably going to, want to thread the Barrel / install, a Brake for, the .300 WSM's, Recoil to "work up loads" ( as NO Fun, on, the Bench ! )
Somebody will come along and recommend Bullets for you ( I know that, a 180 -200 grain AccuBond would work fine but, there are some GOOD High BC, Berger Hunting Bullets available, too . I shoot, a .270 WSM with, 140 gr. Berger Classic Hunters, for Elk, in mine @ 3,185 FPS.
As, stated by, willfrye027 above, the Tikka Barrels, ARE,. quite good and no need to, replace them. All 3 of, my Tikka's shoot,.. 1/2 to 3/4, MOA.
Buy, a good Quality scope that, you can "Dial" elevation and be sure to, Lap the Rings , de-grease and Loctite, the Base and Rings !
The .300 / .338 Mag's, have been known to, "shake off" scopes,.. IF, not done, RIGHT !
Put a Level on the Scope and use, a Plum-Bob / string at, 400- 500 yards to make sure that, the Cross hairs are,.. Straight !
Check for scope alignment, by shooting Bullets at, a long "Cross" on, a "Tall Target".
Then, put your Money into, quality Bullets / good, Hand Loads, Learning to shoot in, the WIND and more, Practice from, Field Positions !
Good Luck !