All of the firing mechanisms are attached to the main rifle assembly - the pistol inserts from the bottom to provide the rifle grip (the pistol also hold caps for authentic firing sounds). The main ammunition includes various sized white bullets that "shoot" from the barrels via spring-action. The rockets and grenade also fire via spring-action. The weapon features a working bipod that provides stability for the various rockets and grenade. The stock can be removed to shorten the weapon while in Tommy Gun mode. The toy when fully assembled is over three feet long and weighs about 4 pounds.
A grenade launcher is located on the main body, above the pistol grip. The launcher extends upwards, and the spring loaded grenade is launched by depressing a button on the side of the rifle.
A red missile fired from a launcher located on the right of the main rifle shaft. The firing button is placed underneath the launcher.
A large green shell which is spring launched from the front of the rifle directly underneath the front sight of the rifle. The firing button is on the left side of the rifle.
12 white bullets are fired from a fixed magazine on the rifle. The bullets are fed into the chamber by a spring loaded bolt.
A lever is pulled to create a "rat-a-tat" noise.
The cap firing pistol could be removed from the gun.
A folding stand.
Topper also marketed additional toy accessories to be used with the Johnny Seven O.M.A including a helmet and walkie-talkies. Deluxe Reading used the Topper Toys brand to add a modern flair to their new product lines. Deluxe Reading was famous for creating huge package playsets that could be seen by children when viewing the top, unusable shelf in grocery store chains. By creating large, colorful boxes, the space could be used to market to the children that always accompanied parents while food shopping. An unusual marketing "trick" that worked well for Deluxe Reading and later copycat toy companies such as Remco.
Deluxe Reading produced many memorable toys including the Johnny Lightning cars (similar to Mattel's Hot Wheels), the Crime-Buster Gun (similar to the O.M.A only geared towards kids play-acting cops and robbers), the Operation X-500 Space Base and others.