Fully modded GRA AMR with explosive rounds wrecks deathclaws.
With the bonus damage using explosives perk you will 1 shot just about anything on Very Hard difficulty and if you don't they will be thrown to the ground and crippled all over. I have seen 1 shot kill more than 1 deathclaw due to the explosive radius. I try to avoid using that combo unless I really do not want a challenge.
EDIT: It is pretty much the only way to get sneak criticals with an explosive device.
With the bonus damage using explosives perk you will 1 shot just about anything on Very Hard difficulty and if you don't they will be thrown to the ground and crippled all over. I have seen 1 shot kill more than 1 deathclaw due to the explosive radius. I try to avoid using that combo unless I really do not want a challenge.
EDIT: It is pretty much the only way to get sneak criticals with an explosive device.