I am also going to have to buy some 5ml barrels as im doing exactly the same as you...

ATM im pinning 2.5ml 3 x per week and splitting it between the partner bodypart (L Glute R Glute for ex...)

I am just pulling out after i have put half in and then going into the other side...

I want to get some 5ml syringes so i can do 2.5ml into each side.... You should try splitting it up like what Im doing if u dont wanna put it all in one side