My last range trip lasted three and a half hours. We brought three guns only and hand three people alternating on a single firing point. No rapid fire, one zeroing. Ended up shooting about a hundred rounds each of .308, .223 and .22. So 300 rounds total on a very slow range day.
Assuming just one range trip per month weapon, it still works out to more than a case of ammunition per caliber just staying in practice. Had we done movement drills or run three firing points, the ammo consumption would have at least doubled.