[tomkat]

nope, it's a legend.

100y x 3f = 300 x 12i = 3,600
40y x 3f = 120 x 12i = 1,440
3,600 x 1,440 = 5,184,000 / 6000m = 864min
or, assuming two cannon @ 6,000/m
5,184,000 / 12,000 = 432min

but per sf: 300 x 120 = 36,000 / 12,000 = 3min/sf

that's still a lot of lead

[gratefulwharffratt]

40y x 3f

Sorry Dude, football fields are 50 yards wide.