I don't know if US Armor units still have a canister round. The round was filled with steel ball bearings and was quite effective from what I have been told. During the Vietnam War US Army field artillery and Marine artillery units were issued the beehive round for anti-personnel missions and apparently there was also a canister round similar to that issued to tank units. Neither, unfortunately, are produced for artillery now. What is used, and is also quite effective, is a high-explosive round with a time fuse set at muzzle action, which is about 2.5 seconds for 155mm howitzers. I've fired it and it is quite impressive. The fragmentation effect from the round is quite effective, though I've only used it in training and not against troops. For longer ranges, DPICM, Dual-Purpose Improved Conventional Munitions is very effective against any target on the battlefield-troops, armor, or soft-skinned vehicles. I have seen the results of that in combat.