So firstly, I call it pretty ignorant when some people trigger me and then don't tell me what exactly they are talking about.
So there are already different rifles in 20mm, 23mm and even 30mm. Most of them are ugly and built in countries far away. To anyone who is concerned about the recoil. There is always a way to handle recoil. Just look at the image below. No matter if 20mm,23mm or 15mm,17mm,18mm wild cats, all it takes is a lot of money. In theory, step one, pay $$$ to a company that develops a premium 20mm action. Step two, pay $$$ to an smart engineer to develop a new 17mm elr cartridge. To keep it simple, now it only takes custom brass, custom bullets, primers, the right powder, a hugh 52" barrel and a chassi. So, I can't see a problem that can't be fixed with money.
Unfortunately no one wants to spend a million and most people do not have millions of $$$$.