Bottom line is that it is hard to go wrong with just about anything off the 308 case. If the deer are big I would not go less than 6.5mm. If the distances are long and/or conditions are windy I would not go more than 7.62mm. If I was starting out custom why not go with AI (you can still shoot factory ammo in 7mm and 7.62mm) plus you get the added benefit of larger case volume (most likely more velocity and better case life). I started shooting a 7-08 last year and it has done very well in silhouette competitions and on 2-antelope and 1-muley.

Deke.