Possible build: 5/8/4/1/6/6/10
4 EN? 6 IN and no BRoF? No Small Frame?
Pick small frame, remove 1 point from IN and give 2 points to EN atleast.
Or take also 3 ST and give 2 to PE. With 3 ST you'll use 10mm pistol on mutated moles till 21st, then use buffout to get 5 ST.
Or let 4 EN, 8 PE, 9 LK and 3 ST and give 4 points go AG, but if you'll be caught in wrong place in wrong time, you'll die a bit faster. But never take 4 EN, I was killing 4 EN sniper many times, and it was really easy, just shot his head once or eyes, blindness and knock out often, and if I get to him with my p90 it means he is dead, I don't even need good critical. 6 EN and x1 toughness on 3rd level, awareness is a waste.
If you want to create ultimate mega ew-sniper machine, then it's:
1/10/8/1/5/6/10
On psycho,buffout,nuka,cigs it'll be:
4/9/10/1/5/6/10 and +15% DR.
without psycho and without cigs:
3/10/10/1/5/6/10
x1 Toughness
x1/x2 Lifegiver 192/220 HP
x1 Weapon Handling
x1 Better Criticals
x3/x2 More Criticals 20%/25% crit
Tag: EW/FA/Doc.
Traits: Small Frame/Good Natured.
with BA on psycho and x1 toughness you'll have DR/DT 60/10.
without psycho DR/DT 45/10.