Seeing is believing ! A mate that re-barreled a T3 Varmint 22-250 to 6mm Rem that would better suit his long range requirements shoots into 1 1/4" @ 500 yds and at velocities that you don't see in print ! His bro and bro inlaw shot 223 T3 Varminters into 2" with 69gr Bergers. I know of others that have bought the T3 Sporter in .260 Rem and in very short order gone on to win 800yd matches. It can be done, Tikka tubes are good tubes ! Of all the rifles I've seen shot in from new, Tikka tubes consistently copper foul the least such is their quality of tube finish. That does lead to the risk of overlooking copper fouling further down the track and risk of the tube drifting 'off song'.