It's good to have friends. One of mine is one of those wonderful individuals that has all the licenses etc. to manufacture bang sticks w/ fun switches, cans, and all sorts of other goodies. He also really likes to show off these toys to his friends and take them out to play when he can.
While I was over there working on a transfer the other night, he asked if I was in a hurry. I replied 'Not any more' when he pulled out a custom rifle (probably costing more than I make in a year) w/ custom suppressor. It fired what is called a 'Wildcat' round, all custom machined, in a caliber called .510 Whisper. Basically a .50bmg bullet in a cut down .338 Lapua casing. I got the fun of firing an API round at a 150m target. No hearing protection. It resulted in a pop.... BOOM!!! followed by schoolgirlish giggling.
Some of the other rounds he's made for various guns:
Hopefully I'll get to test some of these as well. It's good to have friends.