You might try adding in some intensity techniques? When I do calves I'll generally pick a weight that I can get 8 or more solid reps in. I'll do 6-8 straight and strict, then I'll start bouncing lightly in the bottom position and use the rebound to get up and get a hard contraction, I'll do that for a few reps, then I'll hold the contraction up top for 5-10 seconds, then I"ll slowly lower and hold the stretch for 5-10 seconds, then I'll try and rep as many as I can until the burn becomes intolerable. Calves get pumped so good I look like a gimp after a hard set when I walk to the water fountain lol. Might be wroth trying, and btw, I don't neccesarily do ever ything in taht order because I train calves by feel too. Add in the stretch hold and contraction hold and you should notice a nice burn from it.