Bullet concentricity never received much scrutiny from the gun trade and none from the writers until recent years as occasional mentions.
The penny dropped for me when people using old rifles such as the pre 64 started resporting best ever groups.
Becase these older rifles still largely had their original barrels, it became somewhat axiomatic that bullet concentricity was the improvement factor influencing this change.
This was starting to become clearer in the years before the Barnes X, where CnC bullets were still the most common usage and there was a sliver of design changes becoming points if marketing focus that would come to rely upon concentricity to work properly.
Could you imagine the complexity of a Winchester Failsafe bullet (outer jacket, inner lead core, steel shaft insert into rear core, capped off with a base plug, assuming steel again to square up that base but being an insert that still allowed for obturation) shooting accurately without having focused on basic reaearch and improvements before hand?
No, bullet manufacturers have always accepted the challenge but bench shooting of hunting rifles post war due to the proliferation of scope usage tended to swing riflemen towards whatever their rifles preferred.
This gave rise to the higher quality bullets we have today, the best in a lifetime.
