How about if they just made the guns. How would gun control prohibit that. It’s not exactly rocket science. A revolver is close to 200 year old technology. The materials (steel) can be obtained at any junkyard, and the tools at any good hardware store.
Back in WW-II, the British developed the Sten submachine gun. It was specifically designed to be manufactured in garage shops.
During post WW-II British occupied Palestine, the Zionist had a shop that was turning them out by the hundreds. The shop was located in the basement of a laundry that served British officers, the very men in charge of making sure that neither the Zionists nor the Arabs got ahold of arms. The sound of the washers and dryers doing the laundry of the British officers covered up the noise of the gun making operation in the basement below
HEre are the plans for the Sten in PDF form.
milsurps.com/content.php?r=422-Blueprints-for-The-STEN-MKII-(complete-machine-plans
Anyone who has taken a high school shop class has the necessary skills. Contrast that to the chemistry skills needs to run a meth lab. If a criminal can find someone to make and sell meth, why would it be any harder to find someone who can make and sell them a gun? Even a submachine gun.
Why so, are they worse shots than the police?
At least being in civilian dress, they have the element of surprise against the aggressor. A police officer in uniform would most likely be the first target.