Um, that’s a negative sir because I’ve had buildings completely blocked off with 6-7 claymores. Especially that big building in the quarry with all the catwalks and tunnel. I’ve had 1-2 claymores in all entrances on that thing while hanging out way up on one of the beams shooting down at the morons who still get through. 
(this is on PS3, not xbox)
they disappear when you get off’ed.