You real need a bit more info on the property you will be hunting and find out what would be a long shot. A 308, 7-08 or 260 could be ideal. But if a 400 yard shot is offered a 7mm rem mag or 270 might be better. Even think about where you hunt, If a 300 yard shot is long stay with a nice short action rifle. For most any caliber from 260 on up they bullet choice are very bug and most anything in the 120 gr on up will do nicely on deer. The 7mm rem mag well do about anything from small southern deer over clear cuts to moose with the right bullet and shooting to 400 yards with a 300 yard zero is very practical to do.
Rifles. Check out Montana Rifle Company
,they have a new line. The American standard rifle. A little high but a rifle to pass along in the family. Can't buy this quality any more from the big boys. I use a ruger.
TLuker HAHA 303 being better!!