Attorneys for the Maryland State Rifle and Pistol Association and the National Shooting Sports Foundation on Friday filed the 325-page petition to the U.S. Supreme Court on behalf of Stephen Kolbe and a series of gun stores and shooting clubs asking the court to protect popular semi-automatic rifles and magazines from prohibition. http://www.guns.com/2017/07/24/maryland-assault-weapon-challenge-appealed-to-u-s-supreme-court/

"Upon review of all the parties’ evidence, the court seriously doubts that the banned assault long guns are commonly possessed for lawful purposes, particularly self-defense in the home, which is at the core of the Second Amendment right, and is inclined to find the weapons fall outside Second Amendment protection as dangerous and unusual..." wrote U.S. District Judge Catherine C. Blake...

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To explain this, she noted the Supreme Court indicated in Heller that military grade M-16 rifles could be banned as dangerous and unusual, then went on to write "Given that assault rifles like the AR-15 are essentially the functional equivalent of M-16s — and arguably more effective — the same reasoning would seem to apply here."

Blake also found in her ruling that rounds fired from assault weapons have enhanced penetrating capabilities and therefore pose a higher risk to both law enforcement than the bullets fired from other types of firearms. Nevertheless, when plaintiffs questioned the practice under the ban of allowing retired law enforcement officers to receive and keep assault weapons and large capacity magazines, she dismissed the objection saying, "they are better equipped than the general public to handle and store firearms safely."