Injuries, Firearms, Shock and Major Wounds

[Pimpão]

Say a character makes a single attack with a pistol, shoots 3 times and hits two shots in an NPC that has 10 HP. The penetrating damage is 4 for the first shot and 3 for the second one, both in the torso. The NPC is now at 3 HP. Questions:

1. Is this a single injury and thus a Major Wound? It's two shots, but just one attack - one source.

2. What's the shock penalty for the NPC? -3 or -4? Do I consider the highest of them or should I sum the results (and in this case apply the max penalty of -4)?
2.1 If penetrating damage were 2 and 1, the shock penalty would be -3, -2 or -1?