Wait a minute!
The dude has a gun and just happens to prefer breaking people with his hands?
But he HAS a gun, right?
So the only correct answer is NX + X where X = People and N = remaining number of bullets.
If you people don’t stop bothering me with facts, I’m gonna scream! 
Fine. He has a gun. But it’s my office, and immediately after the second guard goes down, I leap upon him and wrestle him for the gun, forcing him to use shots 3-6 on me. My death causes quite a commotion, as everyone feels obliged to stop and say, “Wait… SKALD sacrificed himself for the good of others? This must be some sort of trick. Make sure the Rhymer’s dead!”
That would be me. Me and my 357 Magnum. We make a hellovateam.
Well, yeah. But obviously I mean in cases in which nobody a gun at hand.
I can probably only take out about 7 or 8 guys.
Wait…Skald’s dead? …and here I was relying on you to beat him to death with the truncheon that you showed us all in another thread…
Well, my partner and I were very good with our nightsticks, and two of us could not take one dude down. Now, he was a 350# Samoan. Trust me,* he* was a badass. It took 5 dudes to take him down.
I even used my patented kidney strike, and it just bounced off. :eek:
It’s this reason alone I’ve created a swarm of Jackie Chan clones to work in every office I’ve ever worked in. You never know when The Foot Clan is going to break in and wreak havoc.
Fortunately in my office at the Amalgamated Nunchaku & Ninja Sword Company, I don’t think there will be a problem.
Who doesn’t?
Or let’s just say his gun jammed.
I would go with a variation of the classic Brannigan Gambit: I’ll send in wave after wave of my co-workers until the psycho eventually tires and collapses.
Then I’ll run up and kick him in the 'nads.
'Tis a rare krav maga practitioner indeed who can still do all those Jewdo tricks after he’s been shot 8 times with a .45, 13 times with a .40, or 15 times with a 9mm (depending on what I happen to be carrying that day) and then 5 more times with a .38 special (which I have always).
3, then five to hold him for any length of time.
One to shoot him in the face with the fire extinguisher, and two to knock him down while he’s clawing at his eyes.
Barring any outside utensils, I’m betting the average office is Owt O’luck. The reason being that we can not coordinate or agree on whose in charge for the normal, everyday stuff we do and in which we are all experts. Stuff we’re all willing, able and unafraid to do, and with no pesky instincts trying to drag us out at the last moment.
But OK, my mechanical, “what do I think?” answer is 5. four in front to force/break his fall, one behind to push him down. Then one on each arm/leg and one sitting on his back until the police come.
There’s a good possibility that some of those thugs have knives on them, and in any event they are likely to be much better fighers than the average broker.
This (like many of the other suggestions here) seems to be assuming the guy has no mobility and just stands there waiting for you. I can’t see this working against an experienced martial arts guy. As you come charging at him he leaps to the side and shoves the table sideways, throwing both of you offbalance and the rest follows. Then on to the next victims.
Unless that doesn’t work as well IRL as it does on TV. 
No one has a gun, 'Pup. They work in one of those offices, like mine, where you can bring a handgun so much as into the parking lot (even if you have a valid concealed carry license) without risk of being fired.
Well then, I guess I shouldn’t even bring up the flamethrower…
My combat arts training was almost entirely real-world based. My sensei, who had multiple real world fights under his belt and was one of the early instructors in the Marine Corps Martial Arts Program, told us many times, “By the time you’re done here, you will be able to beat any two regular men in an unarmed fight. Any three men and your odds drop to less than half. Any four men will kick your ass, every time.”
I’ve never had to put that to the test, but it always struck me as a good rule of thumb.
I’ve been told by people familiar with martial arts that they are overrated in the public perception, as compared to an “ordinary” experienced street fighter in good physical condition.
But in this case, the OP specified that he was a “6’5”, 250-lb psycho whose spent his life mastering Krav Maga", so I’m not sure if your sensei’s rule of thumb applies.
(FWIW, my impression is that krav maga is geared towards making a quick strike and escaping, rather than sustained combat, so I’m not sure if it’s the most appropriate martial art for this particular scenario.)
For a data point…
I personally know someone who was jumped by 6 street toughs (in a gang-grudge-revenge motivation incident), and wiped them all out in under a minute (there were friends that witnessed it that didn’t join in the fight, since they thought the 6 guys were also going to turn on them). The 6 guys were people who were known for being street guys who had been in many fights previously. He’s a badass muscled-out martial art cross-trainer.
I sparred with him once (me being a cocky over-confident green belt), and I never managed to even throw a punch. In one motion, he snap kicked me in the groin, and then the throat, and I went down :eek:
Similar to the saying from my classes…we described it as an asymptotic approach.
After some initial training, you’ll defend yourself against 50% of attackers. After a year, 75%. After 5 years, 90%. After 10 years, 99%. You will never reach 100%, there is always going to someone meaner, stronger, or luckier than you.
Yeah, this brings up a good point…knowing “martial arts” of any type isn’t the biggest part of winning the fight. The conditioning and general muscle memory is what helps you out. If you can throw a kick faster than most people can react, you can probably take out 2 or three guys before they even know what hit them. The other three are going to be taken aback, and with that surprise, you take them out as well. Obviously, even Chuck Norris doesn’t prefer this as his method, and would just igve up his wallet. But if you have no other options, using what you know and having your body conditioned is invaluable.