The cheapest you are going to get in for is $4000 for the M11/9 with a Lage .22 upper.
American 180s with those big drums are reliable and throw a couple hundred rounds downrange. They are rare and go for about $10,000.
Your most versitile option is a registered receiver AR-15/M16 with a dedicated .22 upper. You can switch to any upper. The RR will set you back about $8000 if you get a decent deal. They can be picky.
Norrel full-auto trigger packs for 10/22s run around $9000. Finding a reliable high capacity magazine can be a problem. The steel lip 30 rounders work.
Last edited by mboylan; March 31, 2011 at 05:12 AM.