Every manufacturer is the same, handloads void the factory warranty. Be it handgun, hunting rifle, or target rifle. Weatherby does not warranty their sub MOA rifles with handloads either, they have set factory loads they warranty the gun for. No company can guarantee how you hand load, so they cant say how consistent your loads are, or how safe they are.
FYI some higher end rifles don't follow this factory load rule - i.e. - Cooper/Greybull and a few others have a 1/2moa guarantee that is only WITH handloads. They won't warranty accuracy with factory fodder, however they do give you the load data that they use.
Back to original topic, yesterday we were at the range doing some longer range plinking - water filled pop cans at 550 yds - Tikka T3 lite 22-250 55r got 1/5, rem 5r 308 168gr got 3/5, rem/krieger 223 80gr got 4/5, as did the stock savage 12 LRPV 308 168gr. All handholds 'cept the 250.
Not putting the Tikkas down but if you want good accuracy with a Tikka, look into minimum a t3 Varm, t3 TAC, or CTR, or Sporter models - in the smallest caliber that will do the trick for you. IMHO the larger calibers recoil will cause too much wiggle with action/stock (don't believe me, take out your recoil lug and look at it - if it is peened, that means your action is moving - not good for accuracy). The T3 lites are good hunting rifles, well made, but not made for target shooting. There are better options in the Tikka family, as listed above.
There was a wicked beautiful 595 on EE a few months back - that is a real nice gun and probably a great shooter!
There is no doubt that the Tikkas are a well made rifle, and good shooters out of the box, and prob better than most. I don't disagree with that at all. But if you are chasing precision, the savage/remmy/Tikka/custom discussion will live on forever, just like chevy/dodge/ford thing. As mentioned, get what suits your budget, and moreso suits your needs for what you want to do. If you want a butter smooth action, IMHO, get a Tikka or a Cooper, or the like - if you want a tack driver, get a high end Tikka ($1600+ for sporter, CTR, TAC), Savage (seems like the more you spend, the better the chances of NOT getting a lemon) , or rem (again, spend a few $$$, like the savage - 5r for example) or go custom(almost same price). I think I would be safe in saying spend min $1000 and up for the rifle.
And regardless of factory ammo accuracy guarantees, the ticket to small groups isn't just the rifle - precision loading makes up a big part the equation, as does shooters technique. Practise practise practise!!!