There are some quests spoiler ahead so beware! I will try to keep the detail to a minimum.
Basically I am trying to clear out a certain location that has a certain deathclaw in the witch muesum.
What kind of weapon can deal substantive damage to a 30 level or higher deathclaw?
I do have a companion with me and I can sneak him/her close and deal some proxy damage that way. But we all know they take forever!
But otherwise I don't have lot of option because of the location which is indoor especially grenades and other that does aoe explosive.
Best Answer
Although it's possible to defeat the deathclaw through conventional melee- or weapons combat, that requires at least a moderate-level character with reasonably powerful weapons and upgrades.
I've gone through this quest 4-5 times and always use this strategy. This won't let you take out the deathclaw as a level 5 character, but it lets you win the encounter with a lower level character than using a conventional head-to-head combat approach.
If you run out of grenades you can repeatedly peak around the corner for 1-2 shots with whatever weapons you happen to have on you, aiming for her head to maximize damage. But this takes a long time. Your best bet for a quick resolution is explosives and cowardice.