They are all built the same way , primer, brass case , powder and bullet. We need to think outside the box ! Manufacturers and wildcatters for over a century have basically made in some form or another of the same thing where ammo is concerned, stretch it out , shrink it down, neck it up, neck it down, put more powder in it , there isn't a whole lot that hasn't been done by wildcatters , just may not have heard about it or not published. The problem with gun builders and ammo companies in general is they are slow to react, more traditionalist in practice which is probably ok for some people. This bleeds down to powders to a certain extent, bullet makers for sure, these guy's can built pretty much whatever you want if they wanted to. The buying public is driving the market. Things that should have been perfected by now are caseless ammo been out since the late 60's. Telescoped ammo a work in progress, composite ammo in the works, Sigs new fury type ammo looks promising as a step in the right direction I guess. These really are Military driven projects for the most part imo. We need new and more outside the box (ammo capabilities that are way more advanced futurist comcepts) and the rifle builders, ammo & propellent makers will follow. This is where bullet and propellent companies need to lead rather than follow, (notice I didn't say powder) we need to look in a different direction and alternate ways of getting the bullets/projectiles out the barrel. I'm not so sure looking at smoothe bore , sabot, fin or orifice stabilized guided small arms munitions isn't that far in the future if not already here. Recoiless small arms handguns, rifles & shotguns should be way farther along in development.