We always want something better. So we (as in the U.S.) spends tons of money to try and make the next big thing. (Come on eggheads, where are our directed energy rifles?)
It was recently announced that one project is this screw breach to allow for higher pressure rounds. The idea is to use something like this, along with other changes like a squeeze bore and or a collet chamber to allow for much higher velocities and chamber pressures. The article over at techlinkcenter.org says that the Army’s current prototype with a 24 inch barrel drives a bullet 4,600 – 5,750 fps and has nearly double the chamber pressure of a M4.
I sorta get the feeling that small caliber high velocity has been done before, but what do I know?
I would be worried about how well the screw breach handles dirt and debris. Also how bad a catastrophic failure of the firearm is at 100,000 psi. But both those issues should be manageable with good design. The real question is going to be if it gives enough of a real world benefit to make it worth while.
Just because you make something new doesn’t mean that everyone will want to use it. IWI is making a standard rifle called the Camel to compete with their bullpup Tavor/X95 because so many markets are not interested in a bullpup.