Ah! well, don't get excited, this ISN'T a generic gunnery technique. You ought to consider the nature of your ACM, your favourite aircraft and its armament. MGs need either tracking shots or the old 'strafing-a-point-in-space' approach, which I'm sure can be found elsewhere on the forum. I think I even uploaded a copy of 'Bag the Hun' somewhere abouts for that sort of deflection shooting thing.
This approach is intended for crossing shots which is what my ACM generates the most. Also I have cannon and I've noted that 5-7 rounds in a concentrated space are enough to do the job which is just a tiny burst. I'm not a firearms owner, never fired a cartridge-based gun or ever had a lesson. I've watched some videos from Hickock45 etc but didn't find their aiming technique very applicable to AH because my targets are far from stationary and, well I'm a very unreliable component in a machine. So lining up the sights and all that procedural stuff doesn't work so well for me, I usually don't have time anyway.
This technique is based on the different allocation of focused and peripheral attention. So instead of focussing on the sights and having a peripheral focus on the target and hoping for the perfect moment with my tongue sticking out when they line up I'm doing it the other way around. I watch the target, track it visually and especially learn it's movement and at the fringe of my attention I'm aware of where the boresight is. That's why I needed a very bright and noticeable one. Then I just let the burst out when it feels right. No trying to force the shot or get a kill. A bit like that thing Kwai Chang Caine said: The bow, the pole, the archer, not separate things, not many things, but one.
I've noticed it gets easier with time so suspect brains are quite good at this 'learning to catch and throw' business instead of tying to become a lead-computing gunsight. Also seems to inherently get rid of gold-shyness and twitching when you shoot because you aren't focused on sights at all.
Just give it a try and see if there's anything in it for you. Enjoy!