Believe me, I look forward to firing one myself!, we just have to go to the big machine gun shoot at Knob creek in Kentucky and hand someone $30.00 for a belt of ammo, completely legal. Mine were built using fake receivers (philidelphia ordnance), it is the only way to keep them legal. I want to build a semi-auto, but nobody has an ATF letter yet on an approved receiver they will share. There are 2-3 different folks making semi-auto receivers and I am sure they submitted samples, it just takes time. Check out this site for info, it is pretty cool.
http://www.mg42.us/index.php? sid=fa...2b91400c8165a9