I have been reading all the replys to your question on the .308, - If it can rag doll a 200 # 2 legged animal @ 1200 Yds, sure can handle a deer. Just spend more time shooting & less time reading the internet. Perfect practice makes perfect. Once you get the feel for conditions and are able to read them as they happen you can stay on the bubble. As far as needing Expensive optics, check out SWFA's fixed power Super Sniper scope line. They do fall off a bit in low light, but are right there with the $1500 dollar jobs in every other respect for $300 bucks. The BBL life on the .308 is good & way better than the mag. rifles.,less expensive to shoot & most important affords practice.
I have been doing this for a long time, email me or check out my web site... rockmillarmory.com & will be happy to help.