depends on the body part your pinning.

for me I pin

3 cc in glute
3 cc in lats
2 cc in delts
2 cc quads
1.5 cc in chest
1.5 cc in biceps
1.5 cc in front delt

I've tried 3 cc in most muscle groups, but what I do above is whats most comfortable . depends on the compound as well, for Tren suspension I generally don't like to pin more then 1cc at a time , where Test E I could probably handle 5 cc