I hate to ask this but ..........why does anybody need a "full-Auto" anything!
Actually you may see entirely new designs that make it quite useful. Current restrictions keep innovation limited.
While the KRISS was not entirely successful, it shows the type of directions things would take. Mechnical designs that counter recoil, direct recoil to different directions, completely change the dynamics of how full auto handles. With a large market it is entirely likely that there would be designs including small compact firearms that could be fired on full auto with little to no recoil.
Constantly cycling rounds and gas and similar channeled energy at a constant rate make this easier to accomplish with fully automatic firearms than semi auto. With only a small jump at the start or stop of firing you could have firearm designs that counter most of thier own recoil with some of the energy of the current or next cartridge. Or alternate how the recoil is applied so every other round cancels out the previous one resulting in no perceived recoil.
Military forces around the world like to have a selector switch, and have on most firearms since WW2. Most modern combat arms for over half a century have a selector switch.
It also allows for use of calibers as defensive calibers that you may otherwise consider inadequate. Including very low recoil ones that compensate with volume of fire. 20 rounds of .22 in a second can be quite effective.
An arthritic grandma should have a lot less trouble operating a fully automatic
.17HMR or .22LR or a similar centerfire cartridge than trying to manage rapid fire single shots with a .45 ACP. Giving a lot of stopping power to people that struggle now.
Then consider as I said earlier modernized technology that reduces that recoil further. It is entirely feasible you could have small guns no more difficult to shoot and keep on target on full auto than a squirt gun.
Some of the PDWs were going that direction. Things like the MP7 and P90. But they were specialized due to the criteria of defeating some body armor (because there is not a civilian market). Remove that requirement and you can open up possibilities even further for low recoil adeqaute damage firearms that send out a lot of rounds in a short time with little or no muzzle climb.
Thinking only of existing full auto designs is limiting yourself to old technology. What they could do would likely advance fairly quickly if there was a large market that allowed innovation, rather than just the current giant military contract or nothing market that stifles innovation.
Short barreled long gun restrictions make little sense especially with a market filled with almost the same firearms without a buttstock with any barrel length classified as handguns.
Suppressors are a safety device. Really we should be having to fight being forced to use them rather than the opposite. That would make a lot more sense.
Automobiles use the same technology, and that is the case with them. Try to remove your muffler and drive around and you will be in trouble relatively soon. That may eventually be the case in the future, where firearm use requires you have a suppressor installed, and not using one is a legal violation.
