John, you've got the maths all wrong fella!
The rules of paintball state that the first ball will always bounce - hence the ole double-tap (none of this dirty bonus-balling for me, thank you very much!
)
So, you take out two balls per oppo player, and five for the chrony (two to side, three over - unless the judge likes your marker and decides he'll do two to side, twenty over)
Making 19 balls for a seven man, or 15 for a five (and if you play over the pond or @ the 10-man in the UK (Nottingham Skirmish is it?) then have a whole 25 balls)
And as for the thread topic:
When bunkering any number of players:
a: under your breath while running chant "owowowowowowowowowow this is gonna hurt"
and
b: run like fcuk