I am a converted bow hunter for the last 40 years. Still hunt WV and Pa with a remington 760 in .270. My son moved to AZ six years ago and I have had a chance to bow hunt mule deer with him. Now I have a chance to hunt coues deer during gun season. He tells me the shots could be between 300 and 350. Should I consider getting a new gun? If so what caliber? If not what weight and factory bullet recomendations. I do not reload and do not know someone who does. Any help would be greatly appreaciated.