Furthermore, most warmachine hunting units are of the skirmisher variety and someone foolish enough to leave a unit less than 8" away from a cannon hopefully has the sense to use the 2" unit coherency and isn't going to provide you than more than a couple of hits with the template.
Actually theharangue, I think you're getting your 40k rules crossed up w/ fantasy. Skirmishers can only be dispersed up to 1". Due to the fact that you don't roll 4+ for partials, and the tendency of skirmisher units to be rather small, they were very fair game for old grapeshot.
I do have nostalgia working againt me too. There had been some wonderful occasions where I'd sent entire CW units packing due to the fact they got rocked so hard by grape. Ah the memories.
Btw George, you've got the new rule correct. Declare target, check range, roll artillery die, roll to wound if target is in range, consult cannon-misfire chart if that's your result.
Of course, a Master Engineer that's hooked up with the crew could still provide his artillery-die reroll.