What is the best recipe for test E at 350 and 400mg?

I think I screwed up somewhere as my 350mg Test E had a fair amount of PIP. OR it could be an allergy to Mig840, not sure.

Ive read that 2% BA, 15% BB is good for 300-350mg, and 2%BA , 20% BB is good for 400mg/ml. Is this accurate?

Which type of oil should I use to avoid any allergic reactions? I am most likely allergic to Mig840. I never had any real swelling until I used it.