Handgun Disarm, Fairbairn Style

I haven't practiced handgun disarms, much. There is one I learned from my jujitsu instructors for when someone is standing in front of you that I like (and I think would work). But this disarm is for someone behind you with a pistol or revolver.

Here is a clip of W.E. Fairbairn himself demonstrating The pistol disarm begins one minute into the clip. Fairbairn is the one wearing the mask (hee hee).

That same move was used by Marc Lawrence to disarm Gary Cooper in the movie cloak and dagger. I've used this clip before, but it really is good

Finally, if these clips do not illustrate the move well enough, here are the steps taken from Fairbairn's Get Tough.
Hold your arms as in Fig. 131.
2. Turn rapidly inwards towards your left-hand side, passing your left arm over and around your opponent's right forearm, as near the wrist as possible, and bring your left hand up your chest (Fig. 132).
Note. - It is impossible for him to shoot you or release his arm from this grip.
3. Immediately the arm is locked, knee him in the testicles with your right knee and chin-jab him with your right hand, as in Fig. 133.

In general, I like this disarm, but there is one major caveat. You have to know which hand the orc is using to hold the gun so that your body clears the muzzle as you turn. I've seen it suggested that you turn your head to the rear as you speak to your assailant in order to catch a glimpse.

I 'd want to practice this one (a lot!) before I tried it.