I use 1200 ft lbs of energy as my limit for deer and 1500 on elk. So you should be fine to 400 on deer with most .308 rounds up to 165 grains using that benchmark. I wouldn't go much farther.
I like to use 1gal milk jugs for field practice at those ranges as they are cheap, about the size of the kill zone, and give a fun report when hit well.
For a good tag, where a shot at a good deer is a real probability I do highly recommend you follow others advice here. Buy 3 or so offerings of well constructed bullers(Nosler Accubond, Nosler Partition, Barnes TSX/TTSX, Swift, Hornady, etc) and see what stays routinely sub milk jug out to that range. Then buy 2-3 more boxes minimum and practie in the field, shooting off a pack.
All 150-165 gr .308 bullets have a BC low enough that their trajectory will be more dependant on speed that bullet shape, so just find one that is reliable and constructed well for mule deer.
I think Barnes bullets are easy to shoot accurately and perform well on game, but with one flaw. If they impact the animal at low speed they don't mushroom enough and you don't get the devastating performance they are known for.
Personally I'd start with the few plastic tipped, bonded offerings as they seem to have the best mix of shape and terminal performance, particularly in those middle ranges. I'd start with the Accubond personally, also because their are a ton of offerings and the cost is moderate.
Good luck.
