My Whitworth .375 is capable of around a 1/3 MOA 3 shot groups if shot carefully and slowly. Normally I a,m too impatient.

I had some 300 gr Kegelspitz RWS ammo, pretty useless stuff, but these were both very fast and very accurate ie 1/3 MOA.

My Valmet 9.3 seems also very accurate, ie each barrel is accurste, not necessary the combination of two barrels, which is still OK.