Each barrel is like a finger print, unique, and each likes/dislikes certain pellets
One barrel may love 4.52 JSB and the same make of barrel on the same type of rifle may hate them but love 4.53
The difference in size will effect how the rifling reacts on the pellet traveling down the barrel, having an effect on the accuracy at the target end.
Its a hard one, without firing the pellets and looking at the results you cant really say which is 'best'
You can buy pellet tester packs which contain a variety of brands and sizes (arround 30 of each) and you can test them and see how t