You have a good bullet. I have killed 4 deer with them, all boom flop. If you are using 150 grs of loose 777 then, as said previously, back it off to around 125 grs. which is about equal to 150 gr 777 pellets. I shoot the 290 TMZ with 125 grs of loose 777, out of my Omega, with good success.
If your 150 gr load is pellets, and you like the way it shoots, then go for it. ( probably 100 grs of loose 777 is plenty, but use what shoots best).
I have a bullet catcher, a 5/16 steel plate on about a 30 deg. angle, at 50 yds. My 125 gr charge, even on the angled plate, nearly goes through. The recovered bullets are completely flat but still in on piece.