when it comes to calf training,their is two schools of thought,some where successfull using heavy weight and less reps,the others where successfull using medium weight with more reps.i personaly had no problems building 20 inch calves using the standard 9 sets per muscle rep range between 8 to 15 but i have fantastic genetics in my calves.
for those who are having difficulty building their calves i have combined the two schools of thought,let me explain,lets say that you are doing two exercises for calves,standing calf and seated calf,four sets each,do the first exercise the standing calf with heavy weight and less reps,later do the seated with medium weight and higher reps,now next time you come in for a calf workout,switch things around ,start with the seated with heavy weight and less reps and then the standing with less weight and more reps,keep on swithing back and forth each workout,let me know after6month if the calves turned into cows.