2-5 Kilo (4-12Ib)- that's the difference between a gun threat and a knife threat. Why's that? Those numbers are the average pressure one uses to pull the trigger on a hand gun. Not much pressure at all. Very different with regards to knife attacks.
This is why the main focus when dealing with a knife threat should be controlling the hand with the knife, then striking. Once the knife hand is stuck, there's little he could do, freeing you to strike him as you please. However, many people confuse this idea when they apply that same principle against a gun threat. Controlling the hand with the gun is not enough, since all he needs to do is pull the trigger. Even if you’re out of the line of fire, what about the people around you? Their lives matter as well.
With gun disarms, too many times I see people training to go out of the line of fire, control the hand with the gun, and then strike a few times-all before disarming the gun. As if the attacker is holding a red rose in his hand and not a gun. The fact that he's getting hit does not mean he cannot, and won't apply just 2 kilo of pressure to pull the trigger. Even if you hit him as hard as Iron Mike, would you bet your life on it? Reality is not the gym.
Bottom line? With a knife threat the focus is on controlling the hand with the knife, thus making the knife useless. However, with a gun threat focus on escaping the line of fire, then controlling the WEAPON itself. That would be the only way to insure that the gun is no longer able to shoot.
ICCS Head Instructor.