The dynamites of this class come in cartridges 4 in (10.2 cm) and up in diameter and in weight strengths from 20% to 70%. Their water resistance is considered good (the gelatin core being responsible for this), but their fume characteristics are rated as poor. Besides providing increased water resistance, these explosives tend to exhibit the higher velocities characteristic of gelatin explosives (10,500 ft/s, 15,000 ft/s, and 17,000 ft/s) (3,200 m/s, 4,600 m/s, and 5,200 m/s), rather than the low and medium velocities characteristic of other straight ammonia dynamite. In addition, the gelatin core assures propagation of detonation through the entire explosives column. Gelatin cored ammonia dynamites also are very useful when an operator wishes to practice alternate velocity loading to attain a more effective one-two punch in conjunction with the use of short period or millisecond delay, electric blasting caps.