Depends. Bottle necked rifle cases are quiet a bit different than straight walled pistol cases. For rifle, I usually fire twice, trim, fire two more times and trash it. Is it a hard fast rule? Not really, each rifle will allow brass to "grow" at a different rate, and RCBS "X" dies eliminate case stretching. For pistol cases, if loading hot 45's, I load twice hot, then relegate the brass to the plinker pile and shoot to destruction which usually is a split neck from being work hardened. Had as many as 50 loads with some brass