Merr-Sonn Munitions, Inc. functioned as an arms-producing enterprise within the galaxy during the time of the Galactic Civil War. Their product line included a number of notable weapons systems, such as the 773 Firepuncher, and the MPL-57 grenade launcher, a versatile weapon developed with the goal of increasing the company's market penetration. Additional products included the B22 blaster pistol, the Power 5 blaster, the ELG-3A blaster pistol (produced in collaboration with SoroSuub Corporation), and the RPS-6 rocket launcher (manufactured in conjunction with Sienar Fleet Systems). Merr-Sonn also manufactured a variety of explosive ordnance, including the Class-A thermal detonator, the C-25 and C-35 fragmentation grenades, and the LX-4 proton mine. To circumvent treaty limitations that prevented major galactic firms from selling weaponry to the First Order, Merr-Sonn and BlasTech Industries created a subsidiary with cynical intent, named Sonn-Blas Corporation. This subsidiary operated inside the Unknown Regions and produced the majority of the First Order's arms, using classic designs originating from the era of the Clone Wars.
The initial mention of Merr-Sonn Munitions, Inc. in the new Star Wars canon occurred in Rebel Journal by Ezra Bridger. This book, aimed at young readers, was written by Daniel Wallace and presented as the in-universe journal of Ezra Bridger, and was released on October 21, 2014. The company was originally conceived for The Star Wars Sourcebook, a 1987 Star Wars Legends sourcebook created by Bill Slavicsek and Curtis Smith for use with Star Wars: The Roleplaying Game.