Try to determine how much hp the oppenent has left versus the amount of rockets left, just assume, that when you first engaged the enemy, they had full hp, even though for all you know, they could be heavily hurt, just assume though. If you have already at least hit the feet of an enemy with 125, depending on their speed switch. If they are a scout, pull out the shotty, anyone else with 125, you may want to rocket their feet yet again. Also try to calculate (the pros can do this instantly) other factors: multiple enemies, distance from you, class(es) your engaging, your hp, your estimate on their hp, etc, these all come into factor. If your fighting enemies who are primarily close range, it's okay to reload your rocket, just make sure they don't run for a hp pack. If they're getting close, rocket their feet and switch, becuz after the 1st rocket, if you rocket again, it may hurt you or just not be effective enough. You just have to use your judgement, and as we get better, our judgement get's quicker. Hope that helps