With this update in mind, editing the post to read as follows...
The other guards and Samuel move to their barrier and then attack the magical Barrier again; autofire vs. barrier (attack rolls below): 4D8+4 = [8, 5, 2, 3]+4 = 22; 4D8+4 = [5, 8, 7, 6]+4 = 30; 4D8+4 = [4, 1, 6, 2]+4 = 17, for...