Is a 0 MOA barrel possible?

[Chronos]

You measure groups centre to centre so if there's only one hole it's zero . No one in competition want a zero group because they can't score it and they disqualify the target. If they can only see one hole they don't know if you fire one shot at the target and the others into the dirt . If the target is backed with rubber it will show very closely grouped shots but if they all go exactly through the same hole again no score . It's a bit of a conundrum , everyone strives for the smallest possible group except a zero .
The argument about the barrel is theoretical because there is many other things that affect group accuracy .
However a super rigid rail gun in a windless tunnel could produce a single hole group if all other variable were right. So the right barrel it's self could be capable used in the right situation .

jack doesnt the backer scroll showing every hole? that's the point right to stop competitors putting two shots on target and the rest in the dirt?

chronos

[Jack V]

The backing rubber will pick up very closely grouped shots that on the paper target look like one hole , but again if they all went exactly through the same hole even the rubber would not show it . I think the main reason is to allow accurate measuring even if the paper target is torn up at the group which sometimes happens and be able to count all shots .