I'm new to this, and am having trouble deciding which rifle to buy. Is there a difference between the TC Firehawk, Thunderhawk, and the Black Diamond? Would any of these be a better choice in 50 cal for eastern deer hunting? I fould a White Shooting Systems 504 cal rifle at a local shop for $279. Is this a good choice? What about a Knight Wolverine? Money is tight, and I need your input!!