I always operated with a cushion factor of having 1,000 rounds of duty handgun and .223 ammo, and about half that in 12 gauge available for each of our direct unit's 12 officers. Our agency required a minimum of two full qualifications per year with handgun, shotgun, and AR-15. In addition, I would set up and administer training courses during annual Refreshers, as well as provide officers with practice ammo for use on our range.
Up until around 2005, I had no problem acquiring ammo, since we were allowed to collect spent brass from a local military base that we then traded in for factory loads with a local manufacturer. That ended, however, when an agency unit in another region went rogue, using free military spent brass to trade for equipment other than fresh ammo. In a classic beauracratic move, rather than simply penalizing them for their misdeeds, the upper echelon decided to end that program agency wide. Following that, we had to cut down on the number of live fire practice and training sessions, and other units in our region underwent similar cutbacks. Ordering from major contractors became a PITB because of spotty, partial deliveries. We compensated on the ammo issues by purchasing a computer run simulator system, and using Simunitions scenario training for our officers.