I learned techniques for disarming someone that had either a handgun or a knife when I was working on my black belt.
It *can* be done. The fact is that if the person hasn't already shot you and is close enough for you to reach the firearm, you have a decent shot with training.
The key is that you are initiating action and the handgun holder has to react to you. Regardless of how fact the reflexs of the other person is, they cannot escape the reality that you cannot physically react fast enough to effectively avoid the disarmament. This is based on our physiology and how the brain processes information.
That said,
If you hesitate in the SLIGHTEST, you give the gunholder plenty of time to process information and take action. If you do not have your technique trained as second nature, you will meet similar results. You don't get to have a do-over if you are rusty on it.
That said,
Only an idiot EVER pulls a gun and gets within arms reach of his intented target or extends the arm fully that close to a target. I was always taught that if you had to be too close to a person, you want to position yourself where your handgun hand is towards the rear and you have an open hand forward.
This allows you to maneuver if the target DOES attempt something. It allows you more reaction time. It makes it much more difficult to disarm YOU.
However, I repeat this. You don't want to be in arms reach of someone if you are the one with the handgun if at all possible.
You don't want to pull a handgun unless you are in a positon to use it-- although I do understand if you have dealt with something like a break-in and you are waiting for the police to arrive.
I used to go to a lot of martial arts training seminars. One I went to was lead by Bill "Superfoot" Wallace-- a kickboxing champion from the Golden Era of Kickboxing. As expected, there was that one person in the crowd that asks him what he would do if someone pulled a gun on him.
His anwer was classic:
"If they shoot me, I am going to bleed. If I bleed too much, I am going to die."
He went on to explain that martial arts is not some super-secret ninja skills where you can suddenly deflect bullets. He said to think of it as one tool on a swiss army knife. There will be tools for each task, and hand-to-hand is often the one of last resort.
John