My brother loves his 7mm-08. I believe it is exactly what you are looking for. The .243 may not carry enough energy at 300 yards so I would leave that one out. The .257 Roberts and .260 are good substitutes. The .308 is good if you plan tohunt larger game in the future. That covers the short actions. On the long action side, the 25-06 can't be beat. The .270 and .280 are good also.