Note how the list armament ALREADY INSTALLED on the ships in question. They do not actually authorize those ships to be armed at all. Only commissioning their usage for US military goals. Also, the privateer gets to keep the guns on any ships he takes.
James Madison, PRESIDENT OF THE UNITED STATES OF AMERICA
To all who shall see these presents, Greetings:
BE IT KNOWN that in pursuance of an act of congress passed on the twenty-sixth day of June one thousand eight hundred and twelve, I have commissioned, and by these presents do commission, the private armed Brig called the (Name of Vessel) Prince of Neufchatel of the burden of three hundred and nineteen tons, or thereabouts, owned by (Owners’ Name(s) John Ordronaux and Peter E. Trevall of the city and state of (City) New York and (Owner's Name) Joseph Beyelle of (City's Name) Philadelphia in the state of (State) Pennsylvania mounting eighteen carriage guns, and navigated by one hundred and twenty-nine men, hereby authorizing (Captain’s Name) Nicholas Millin Captain, and (Lieutenant’s Name) William Stetson Lieutenant of the said Brig and the other officers and crew thereof to: Subdue, seize and take any armed or unarmed British vessel, public or private, which shall be found within the jurisdictional limits of the United States or elsewhere on the high seas, or within the waters of the British dominions.
And each captured vessel with her apparel, guns and appurtenances, and the goods or effects which shall be found on board the same, together with all the British persons and others who shall be found acting on board, to bring within some port of the United States;
And also to retake any vessel, goods or effects of the people of the United States, which may have been captured by any British armed vessel, in order that proceedings may be had concerning each capture or recapture in due form of law, and as to right and justice shall appertain.
The said (Captain’s Name) Nicholas Mullin is further authorized to detain, seize and take all vessels and effects, to whomsoever belonging, which shall be liable thereto according to the law of Nations and the rights of the United States as a power at war.
And to bring the same within some port of the United States in order that due proceedings may be had thereon. This commission to continue in force during the pleasure of the President of the United States for the time being.
GIVEN under my hand and the seal of the United States of America at the city of Washington, the twenty second day of December in the year of our Lord, one thousand eight hundred and fourteen and the independence of the said states the thirty ninth.
By the President, James Madison James Monroe, Secretary of State