It may be a hard pill to swallow, but these subguns, and machineguns for that matter, weren't designed for the hobbyist. They were design for a tactical employment, not for an afternoon outing. Cost of ammo and reloading means zip. In the case of an Ingram, they were designed to deliver massive amounts of lead in a CQB situation. Ambush/Counter-ambush. When Ingrams were employed for Ambush in SE Asia the assumption was everyone in front of the gun was a BG. In Counter-Ambush the same held true. Oh, and they are a joy with a can, scary as a Liberal without one.
The M11 in .380 with a can is BIG fun, pricey, but big fun.