In 1957 when new condition O3A3 Springfields were $15 from the DCM a hot topic by CB shooters was whether the 2 groove barrels would shoot cast bullets better than 4 groove barrels. Those favoring the 2 groove (Which if I remember right included Col. Harrison.) said that because the 2 groove had much of the circumence of the bore at bore diameter, that gave more support to the nose of bore riding bullets and improved accuracy. This always sounded logical to me but of course logic without testing to back it up means nothing. Both of my O3A3s were four groove so I couldn't test.
If we knew the answer we might be able to design a better rifling configuration for CB rifles.
Question: Since our military shooters shoot a lot of bore riding bullets and most of them in O3A3s, what have they found out about whether that old contention that two groove Springfield barrels shoot bore riding bullets better than the four groove ones. Is there anything to it?