I'm at lvl 20 right now but even a young deathclaw is whooping my ass, I'm at a 100 on my guns and have been using rifles,repeaters SMG's and the even LMG against it and can barely do 30% damage while in VATS. I thought it would be a matter of changing ammunition but i read on the game manual that if that shield icon thingy appears on the left hand side of the enemies' lifebar that I should switch to a better weapon. help..??
AP rounds. Buying about 200 of those for the All-American Marksman Carbine made the difference between "Get ass kicked at first encounter" to "success" in the Black Mountain quest against Super Mutant Masters.
if you are properly built, with the unqiue sniper just shoot at them once, than wait for them to come close enoguh for 95% than just pop all your AP in VATS, at x5 crit chance every hit is a critical so they die in a couple shots with better criticals
a sneak head shot from Anti-material rifle with armor piercing bullets and better criticals will 1 shot a deathclaw on any difficulty aswell.