I just took in on trade a Ruger Mark II M77 7mm Rem Mag. The guy gave me 2 boxes of hornady sst 139 gr bullets. My first question is how many guys use a 7mm Rem Mag on whitetail and is the bullet good for whitetail? I really like the look and feel of this gun. Gun has only been shot to sight in. Its like brand new. Thanks for any answers!