Had a mac11 380 machine pistol.
Jumped through the hoops and paid out the nose to buy it.
Went to the public range and was quickly grabbed and disarmed by the range officer yelling at me about machine guns. I had my papers but he had the COs out in a minute to remove me from the range. Only two magazines I've ever shot from a machine gun. No posted rules against it (at the time - they were added later)
I'd bought it registered from an estate for 2k, knowing it was worth 5. Had to pay a lawyer to setup a trust to buy it, and like 20% to the auction house, so it was $2600 home to me I think. Spent a lot of money on 380 ammo, bought a couple extra magazines. But that was its only outing. Wish I'd kept it with what I know now - can put other uppers on there basically using nothing but the serial number on the lower.
The fire rate is insane on those. I think i cleared my two magazines in under 6 seconds even accounting for the mag change. 30rds in a second max.
I thought it silly to own after learning I cant shoot it at any private or public range in the area, and it eats a box of 380acp in less than 2 seconds thats $20/second to run the thing.
I put it on consignment at a local SOT dealer who only wanted 10%. Got $4k so I took home $3600. Subtract the magazines and case I sold it with i probably pocketed $500 through it all. Enough to cover my time and hassle of dealing with NFA stuff.
Just gonna stick to SBRs and suppressors for now. Subguns are fun, but thats the end of it. Can get the experience at a rental range and not deal with ownership.