Makes good sense. Thanks for posting that.

I imagine "exceptional circumstances" would be any time someone was shooting back, among others. At the 1 shot per 3 minutes pace a 3" rifle battery could fire continuously most of the day without needing resupply (ending up with a remainder of canister I suppose.) At 2 shots per minute they would run out of long range ammunition in less than an hour and a half.

That would make sense of the order to pick up the pace to bring things to conclusion.