Txspike,
Good afternoon. I have plenty of range time with the 150 power point out of my 7 Rem Mag. They are a very accurate bullet indeed, however the bullet failed on the one and only deer I shot with it. It anchored her right there in her tracks BUT the bullet litteraly came apart. There was no exit anywhere and I found bits and pieces of jacket and lead all throughout her right front shoulder. The shot was about 85 yards slightly down hil and she was quartering to me (right to left). The velocity at which your STW can attain really puts a lot of demand on a bullet, if the shots are close. For white tail here in Michigan it works fine, although next time I would wait for more of a broad side shot. If I were to hunt anything larger, I would go to a bullet with a thicker shank to help keep its integrity on impact regardless of the shot angle.
Are you a handloader? If you are there are many different options out there. Anyway, good luck and shoot strait.
Flinter54