I tried searching, but the search field keeps collapsing on me. I assume, being a .22lr, and as long as the magazine is a 10rd mag, and barrel 16", it would be legal, but want to make sure first.
I don't believe rimfire lookalikes of the dreaded "assault rifles" are covered. A friend has an MP5 in .22 and I've seen them available at gun shows along with Colt M4's, S&W and H&K M4's and Stg44 replicas.
Either everyone is in violation or they're given the official MSP Okie-Dokie (for now).