Refusing to Let Police Enter W/O Warrant Is Not "interference with A Police Officer."
In Commonwealth v. Adams, the MA Supreme Judicial Court held that refusing to let the police enter your home and seize your guns upon a mere notice of revocation is not "interference with a police officer." This charge is commonly brought against those who do immediately comply with a police officer's orders, even when that order is baseless.
It also noted the district court hearing the case dismissed the charge of failure to surrender a firearm. The judge found that no exception to the warrant requirement
authorized the police to enter the defendant's home, forcibly open his gun safe, and confiscate his firearms and ammunition. This is in keeping with the SJC decision in Pasqualone v. Gately
In short, a good decision. Commonwealth Second Amendment submitted an amicus brief on behalf of the appellant.