How to pester a deathclaw
The new deathclaws form family groups. There are huge Mother deathclaws, quite large Alpha Male deathclaws, basic deathclaws, and baby deathclaws. These canny marauders infest rocky locations, and all types share a propensity to leap, maul and mangle before you're aware they're near by with excellent stealth skills. (There are also Blind and Legendary variations.)
There are only two survival strategies. First, stay far away. And second, take high ground and snipe them with the best long range weapon you've got. These are two: The YCS/186 unique variant of the Gauss rifle, and the .50 caliber Anti Material Rifle. Both are scoped, and both are deadly enough against deathclaws, if you're patient.
Beware. Fully-grown deathclaws can disappear from view. Think raptor pack tactics in Jurassic Park.
Occasionally, you may encounter solitary deathclaws, or a pair of them. In this case a light machine gun can be effective, provided the beasties are distracted by your companions, such as Veronica, who prefers Pushy to any other melee weapon, and ED-E with ranged laser.
By the way, don't overload Veronica with extra inventory. She has a tendency to hang back if her agility is impaired by superfluous weight.