My G2 weighs about 2 lbs less than my Encore (both in .45 cal). That makes a difference!
I wouldn't consider going over 85 grains of powder with anything in that G2 for fear of losing part of my face. But...that G2 is my favorite rifle at the moment, light, quick, and accurate. Works very well on deer. My load last year was 65 grains (by actual weight) of T7 FFg under a 180 grain XTP in tan sabot. That would equate to ~80 grains of that powder by volume. Thinking of going to a 200 grain XTP this fall, but don't want to push my luck.
Can't help you on velocities but if you are planning on pushing heavy loads in a G2......hang on!!