From what I have been told, yes when two rounds are fired the...

From what I have been told, yes when two rounds are fired the second travels in a vacuum,thats what I was told anyway,but the reason why the high velocity is achieved is because when more than one round is fired the gasses behind the first round are recompressed when the second round is fired causing the first round to increase in velocity dramatically, I believe the second round doesn't travel quite as fast as the first, because it has imparted some of it's energy to the first round when recompressing the gasses behind the first, thus the second becomes sacrificial to some extent, but if a third round was fired then the second round would travel at pretty much the same speed as the first round and the third round becomes the sacrificial one, I believe this is what is called Hyperburst when three rounds are fired where two projectiles travel at high velocity directly behind one another,this enables both projectiles to hit the target in exactly the same spot, the third round doesn't travel as fast and falls behind I believe.

When you double the velocity of a something, then you quadruple the kinetic impact,it all relates to E=MC squared.

This part I am not so sure of and I may be dead wrong, but up until very recently, no one had ever fired a weapon so fast that it was possible to have two or even three rounds in the barrel at the same time, all having been fired, this situation changed the physics of ballistics somewhat, but what I am thinking "may" also be possible? is that the last or sacrificial round in the barrel "MAY POSSIBLY?" mitigate some of the recoil from the firing of the first two rounds, I haven't seen this and I haven't heard this mentioned before by anyone, but I am thinking there is a slight chance that I may be right?
If my thinking is correct I believe that some of the forces involved interact with each other in ways that have never been seen before, but as I said this would not have been possible with conventional firing where the first round had left the barrel before the second fires, thus no re- compression?



NB I don't believe you will see Hyperburst used in things like the Firestorm or the 3GL,I don't think you will ever see two rounds that have been fired still in the barrel in those weapons I just mentioned, you will I believe see it used in a rifle or artillery etc, the Firestorm or the 3GL will use a different method of increasing velocity, one that uses a multiple loads of propellant where they can be fired discretely, depending on the KE or the range required.

Hope this helps, but like I said, I may be wrong with some aspects of this, time will tell I suppose?