Systems to measure muzzle exit conditions of for ammunition improve fire control solutions and reduce shot-to-shot dispersion in both conventional and air-burst programmable ammunition. A first system measures muzzle velocity and, when firing “post-shot” programmable ammunition, the system calculates a unique time-of-flight optimized for the actual muzzle velocity and transmits the time to detonate signal by using either optically or radio-frequency signals that represent an optimized time of burst to a projectile. A second system measures muzzle velocity coupled to a ballistic calculator and, when used with ammunition having ferrous characteristics, the force is applied to exiting ammunition to slow or increase the muzzle velocity to a consistent, standardized target velocity. The systems are separately or in combination incorporated into kits that readily improve the performance of weapon systems.