You were badly misinformed.I heard it was the only legal way to carry a magazine with a capacity greater than ten...
Among the questions MSI most frequently encounters are, "Can I keep magazines capable of holding more than 10 rounds?" or "Can I carry a magazine that holds more than 10?"
Maryland law does not prohibit the possession of a magazine with a capacity of more than 10 rounds.
Period, full stop.
Law says this:
A person may not manufacture, sell, offer for sale, purchase, receive, or transfer a detachable magazine that has a capacity of more than 10 rounds of ammunition for a firearm. Section 4-305.1.
And...
be aware that MD Code, Criminal Law, § 4-306(b), provides that a person who uses a magazine that has a capacity of more than 10 rounds in the commission of a felony or a crime of violence is subject to a minimum sentence of 5 years in addition to any sentence imposed for the crime itself. SO, don't use your magazine in any crimes of violence or felonies (e.g., First Degree Assault), and you will be fine.