There are some things that have no substitute. Ammunition is one of those things, when you need ammo nothing else will do but ammo. So how much ammo is enough ammo? I recommend that an officer carry at least two full reloads on their person whenever they are on duty and four full reloads is even better. The officer should carry at least that much in their gear bag, even if it is boxed rather than in magazines.
There should be four times that amount of ammunition at the station, per officer in the agency. Some should be stored as ready ammo in the armory but most should be stored in long term ammunition storage. Long term ammunition storage should be clean, dry, not too hot or too cold and should have limited access to range staff and supervisors.
A major shootout can involve the firing of hundreds, even thousands of rounds of ammunition. A barricaded suspect, an active shooter, a major robbery gone bad call all result in officers needing to fire off all their ammunition in their guns and on their belts. Having extra ammunition to replace that is essential given the nature of law enforcement you can’t wait for a shipment to arrive in a few days. Ammunition can be rotated from duty use to training use as it gets old so having ammunition on hand is not wasteful; that’s what the SGT Says.