I shoot a Remington 700 MZ I found the best load for me is 100 gr pushing a Hornaday 300 XTP mag. I shot the 240 gr for a while but found the heavier bullet performed better. It was more accurate and had better knock down.
Every MZ will be a litlle different I would try different loads and bullet combinations until you get one you like. I agree about using to much powder. I think when you use 150 gr alot of it will get blown out the barrel with igniting anyway.