You are probably right.

Sell everything and get a 280AI. It is the only thing that can do the job. Settle for no more than 1/4" groups at 100, and use only armor piercing bullets. If it can't shoot through a mid-80's GM small block, you'll never be able to kill a sheep with it. Sheep and bears were the original inspiration behind kevlar. Make sure to top it with a 4lb scope with at least 20 power and no more than 1" of eye relief, and get one of those rifle slings with the shooting sticks built in. Don't forget your cough silencer, and be sure to get your rifle bore sighted by a professional at Cabelas right before your hunt.