That first shot with the whip taking out the gun that they determined was "False" is the same problem I have with Mythbusters...Just because the guy throwing the whip there, (who's form was all over the place, and it didn't look like the whip was rolling out incredibly cleanly,) couldn't do it, doesn't mean it wouldn't work. It's all part of this myth that I think needs busted that if a couple fairly clever guys with a video camera can get a show on TV, and they try something that doesn't work, it's instantly impossible, (I know, I know..."The Mythbusters" never claim that, and I don't in any way think that's their intent. In my limited interactions with Adam Savage, he seems to be a stand-up guy who is just happy to get PAID to go out and try all this cool stuff! But so often I hear, "But mythbusters disproved that!" which is utter bollocks!)
Stupid to throw a whip at a guy with a loaded gun? Well yeah, but when a guy with the intent of KILLING you has the thing cocked and pointed at you, what ELSE are you going to do? The whip is primarily effective as a "Suprise Attack." Indy uses it as such. Wise decision? Not really, and I'm sure not arguing the practical efficacy of using a whip as a defence against a guy with a gun. But like the old saying goes, if you're falling out of an airplane without a parachute...You might as well flap your arms and hope A LOT...
Plus, if you watch the movie, Barranca's hand isn't wrapped, it's hit...HARD. The gun doesn't go sailing out of Barranca's hand toward Indy, it gets dropped, and Barranca goes running off into the jungle clutching his hand.
You can take fingers off with a heavy whip like a Morgan. The energy transfer from that heavy mass in the butt end down that heavy thong can easily slice flesh, snap bones, and amputate digits. The slo-mo shot with the bag was @#$%. The thrower was putting NO force behind that throw at all. He hit it with about the same velocity that he smacked the guy who said, "Yeah, that hurt!"
In recent conversations with my friend who knocked a twenty-five-cent piece sized hole in his forearm with a bullwhip, he told me that he didn't think the popper or fall ever touched him. He claims that it was the shockwave from the crack. I don't know if I buy this, but in a 2003 study by Doctors Tyler McMillan and Alan Goriely of the Mathematics department at the University of Arizona, Tuscon, they determined that the tip of a whip can theoretically accelerate to speeds in excess of 50,000 times that of the accelleration of gravity! So, don't give me that a person suddenly smacked with a whip won't drop a gun! They'll drop the gun, their jaw, and probably a load into their underwear.
Also, the guy in the video demonstration was telegraphing...A LOT...At first, he was doing the wrap with a circus crack. Then he switch to a flick when he was trying to cut the bag. The advantage of flick cracks is that they need little setup on their "Load Phase." Watch DeLongis's whip demo, the French "Indy IV" interview, and the Extreme Marksman clip. With a little practice, you can deploy that bullwhip faster than a gun, and once the whip is moving there's not much chance of dodging it.
As for swinging from a whip? Morgan's "American Classic" design was developed partially for Hollywood stuntmen. The wider, overlapping, (what I once called "unbevelled, until Bernardo Del Carpio showed me otherwise on David's and his own work,) strands were MEANT to take abuse that stunt men would have to put them through. That meant lots of wraps, and maybe even swinging from them. This is DIRECTLY mentioned on page 105 and 106 in the second edition of of Morgan's "Whips and Whip Making," in discussing the development of his 450 series bullwhip. Now, it IS doubtful that Mr. Morgan was actually saying that he made his whips to survive the stresses of repeatedly supporting the weight of a grown man. But they will do it. People have described it here. Kangaroo would be better in this than cow, as it will stretch...A LOT, and the braiding of leather has an advantage is that the stress on the leather is distributed, THEORETICALLY evenly over the length of the whip, (unlike a chain that is only as strong as it's weakest link, the strength of a braid is increased with the addition of strands...I believe that multiplies exponentially as well...I'm by no means a mathematician.) The problem them becomes that the leather might not be elastic enough to "bounce back" and remain useful as a whip.
But hey. The whips belong to production company prop departments, right? Not the actors, not the stunt men, not the directors, (OK, sometimes Stunt men, who often buy a lot of their own gear...And who can blame them...Train with what you're going to use. Know what you're going to use.) But if I handed you a $800 Morgan whip, and said, "I will pay you prevailing wage, and get you credits toward your SAG card to crack the end of this over that tree branch and climb to safety while I get it on film." What would YOU do? Say, "but what if it damages the whip?"
So yeah...You can do it with a ruggedly made bullwhip.
However, if you attempt to try it with one of mine, and I'll shoot you before you can crack the gun out of my hand.
Anyway, all the best and happy cracking.
(... and I gotta tell you, unless you're a complete dumdum with a gun, there is no way that trick can beat a bullet, especially if the pistol is already out of it's holster and already cocked, so don't count on it to save your life mate.
I'm curious what happens if we will use roo whip. Will it break or no? What do you think?
TheFish! I agree! To add to it, I have wrapped the whip around the gun to pull it out of somebodies hand before. My friend was holding a airsoft gun and was not a junk lightweight plastic. He had a firm grip around the gun and it was rather heavy. I did manage to pull the gun out of his hand pretty quickly. I do agree though, he hit his hand and he dropped the gun, not actually wrap which is the misconception it seems. 
) and found some of them pliable, and might I add demonstrate a better display of technique than these guys!