Wait what? I created an account just to contest this. I've never ever met a single person who openly admitted to committing a felony my modifying their firearm into an illegal machine gun.
I would most certainly not call that common and I think either you're around the very small minority or full of it. That modification (illegally done) carries a penalty of 10 years in prison and up to $250,000 in fines. I seriously doubt you know people openly willing to share information that could invoke those kind of consequences.
You can even use a different caliber in it like 6.5mm Grendel which is a 1000 yard round.
So you can most certainly use it for rapid follow up shots at long ranges while hunting.