Questions & Answers
Updated November 2, 2010
Q: When you were talking to Bob Mainhardt, did he ever comment on the use of the word “Automatic” on the early cardboard pistol boxes? (Eric Davidson)
A: Yes, he did. The early boxes were designed specifically for the .49-caliber Model 137 pistol. The prototype Model 137 was made in “late 1962.” Production Model 137s would have started a little later, in early 1963. The date on the back of the boxes, 4-63, corresponds nicely with these dates.

As you know, Mainhardt never threw anything away that could possibly be used later. Lots of the Model 137 “Automatic, Rocketeer” boxes were made, but MBA did not sell anywhere near enough Model 137s to the U.S. military or anyone else to use up the boxes. So, when Mark Is were put in the market, and then the transition models with the first slide, and then the Mark I Model Bs, the old boxes were used to store and ship them. That’s why the cutout for the Model 137’s rear sighs does not match the slide-equipped pistols with their different sight radius..

The prototypes and first production models intended for the military were full-automatic, which is why the box says “Automatic,” even though MBA never sold any full-automatic pistol (or carbine) to anybody, including the military, according to Mainhardt.
Q: What started the whole less-lethal quest by MBA?
A: MBA’s interest in less-lethal weapons began in 1968. Gyrojet firearms and rocket sales were stagnant, and the Gun Control Act of 1968 had placed the entire Gyrojet line in jeopardy by classifying 13mm Gyrojet guns (but not flare launchers) as destructive devices. By 1968, MBA had built up a significant firearms and ammunition-manufacturing capability, and Mainhardt did not want it to go to waste as 13mm Gyrojet pistol and carbine production ended. The decision to begin 12mm Gyrojet pistol production on a limited scale had not yet been made. A new line of less-lethal (originally, and wrongly, called “non-lethal”) products could keep MBA’s tools, machines, and manufacturing personnel busy and hopefully make a profit for the company.

At the time, Robert C. Mawhinney was MBA’s Ordnance Systems Manager. Mainhardt tasked Mawhiney with finding out all he could about then-current, less-lethal weapons to see if any of them might be useful to MBA as new products. Mawhinney was surprised to discover that there were very few less-lethal weapons in existence, and that there was almost nothing in the literature about them. Most less-lethal weapons had been quickly developed, tested, and then dropped because they were not effective, too complex, too expensive, not reliable, or all of the above. After taking an inventory of the few products available in the market and evaluating each of them, Mawhinney began a study to determine what was required to inflict “extreme discomfort or incapacitation” on a person in order to stop him or change his behavior without killing him.

According to Mawhinney, in a moment of inspiration the solution “just kind of popped into my mind.” A heavy cloth bag filled with shot could be folded over and loaded in a conventional cartridge case. When fired through a rifled barrel, the bag—later named the “Stun-Bag”—would engage the barrel’s rifling, spin, and open up flat when clear of the muzzle due to centrifugal force. Because a very large bore was not required, the launcher could be of a manageable size and weight. In fact, the largest caliber used with the Stun-Bag was 40mm (1.57 inches). The projectile did not need to have a large diameter when it was fired. It just needed to have a large area when it impacted its target.

On Monday, May 4, 1970, following several days of campus unrest and antiwar demonstrations, four students at Kent State University in Kent, Ohio, were killed and nine others wounded by Ohio National Guard soldiers who were armed only with tear-gas grenades, issue firearms, and ball ammunition. The shootings by under-trained and over-equipped soldiers were extremely controversial, and resulted in antiwar demonstrations nationwide. During research for this book, I spoke with Alan Canfora, who was one of the students wounded that day—he was shot through the right wrist by a soldier firing an M1 Garand—and he was interested to learn that the shootings had been instrumental in motivating MBA to develop its less-lethal weapons.

This tragic event made a tremendous impression on Mainhardt, who became even more determined to provide the Army with a less-lethal option for crowd control. Shortly after Kent State, Mainhardt told Mawhinney to do everything he could to complete work on the Stun-Bag as soon as possible. MBA’s less-lethal development had a high priority, and Mainhardt gave Mawhinney a “blank check” for whatever he needed after an initial project funding of $10,000.
Q: What is a Gyrojet?
A: A Gyrojet is a miniature rocket that is gyroscopically stabilized in flight by spinning around its longitudinal axis, like an American football being passed. Gyrojet rockets range in size from 2.8mm up to 55mm, with 13mm being the size most often seen now. A Gyrojet’s spin is produced by its nozzle (base) ports (holes) being drilled or punched at an angle. Gyrojet rockets were normally made with copper-plated steel cases. “Gyrojet” is also the name of the firearms that fire Gyrojet rocket ammunition.
Q: How much are Gyrojets worth?
A: Gyrojets, like all collectibles, are worth what someone will pay for them; the amount of money that changes hands between a willing buyer and seller. For a collectible to have value, three things have to happen: 1) collectors must know that the collectible exists, 2) collectors must want to have it, and 3) the collectible must be available in limited quantities. The more collectors know about a collectible, the more they want it, and the scarcer it is, the higher the values will be. Until now, there was little information available about Gyrojets, etc., so there wasn’t much demand for the few specimens available. A “standard” 13mm Gyrojet rocket has a value of about $35 – 65 depending on condition. Same for 12mm versions. Other, scarcer calibers can easily bring $200 plus, and the WW II German 9mm “S_Patrone” rockets can top $1,200. Finjets are $200-250 because they are so rare, and Lancejets can be about the same. 13mm and 12mm Gyrojets (rockets and firearms) were the only calibers offered to the public, so other calibers are much scarcer.

Gyrojet firearms range from about $3000 for a cased Mark I Model B 13mm pistol in exc-mint condition to about $1,300 for a Mark II Model C 12mm pistol in its original cardboard box. Condition makes a tremendous difference in value. A mint condition Mark II Model C sold for $2,100 on September 12, 2010, at the Rock Island Auction.

If you have a specific example, I’ll be happy to estimate its value. I have about 500 entries in my database, all of which are actual prices realized at well-advertised, public auctions.
Q: Do I have to go through the U.S. Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) to obtain a Gyrojet firearm.
A: Probably not. Almost all Gyrojet firearms have been designated as Curios and Relics by ATF, and can be bought and sold like any other firearm. A Curios and Relics Federal Firearms License (C&R FFL) is very easy to get and renew, and makes collecting Gyrojet firearms a lot easier.
Q: What is a Finjet?
A: A Finjet is a miniature rocket aerodynamically stabilized in flight by fins, like an arrow. Finjets were MBA’s first product, and are typically 3mm in diameter. They were normally made of injection-molded plastic with steel points, or less-often of aluminum.
Q: What is a Lancejet?
A: A Lancejet is a miniature rocket stabilized in flight by mass being concentrated at the rocket’s nose, like a javelin. Lancejets are typically 1.5mm or 3mm in diameter with some anti-mine versions being 6.35mm. Lancejets often have aluminum bodies and steel noses. Lancejets were designed to be fired in salvos, although some larger underwater versions were single-shot.
Q: What is a Javette?
A: A Javette is a solid, unpowered, sub-miniature, ballistic projectile for use in antipersonnel operations. MBA Javettes were typically half the size of the smallest Lancejet. Some Javettes had threaded tails to hold a biological warfare (BW) or chemical warfare (CW) agent. 0.030-inch-diameter Javettes typically had tungsten noses and magnesium tails. They were fired from modified cartridges and firearms, often silenced.
Q: What does “MBA” stand for?
A: MBA is short for M (Mainhardt) B (Biehl) Associates, typically written with no spaces: “MBAssociates.” MBA was located on Bollinger Canyon road in San Ramon, California. The company was bought by Tracor, Inc. in 1980, and Mainhardt stayed as Tracor/MBA’s president until he left in 1982.
Q: Who was Robert Mainhardt?
A: Robert Mainhardt, 1922-2006, (no middle name) was one of the two co-founders of MBA in 1960. Arthur T. Biehl, PhD, 1924-1993, was the other co-founder who left the company in 1965.
Q: What does “less-lethal” mean?
A: “Less-Lethal” is term MBA used to describe a series of weapons designed to inflict non-fatal injuries on human targets such as rioters. However, if improperly used, a so-called “less-lethal” device can inflict fatal injury, so “less-lethal” does not mean “non-lethal.” MBA Stun-Guns and Prowler-Foulers are less-lethal devices.
Q: What is a “MIRA?”
A: A MIRA is a Dutch miniature rocket (Mini Raket) modeled after MBA Gyrojets, Finjets, and Lancejets.
Q: What is a Microjet?
A: “Microjet” is MBA’s designation for a group of miniature rockets including Gyrojets, Finjets, and Lancejets, but not Javettes, which had solid bodies.
Q: What was Trebor?
A: Trebor, Inc. was the company founded by Robert Mainhardt in January 1983 after he left Tracor/MBA. “Trebor” is Robert spelled backwards. Trebor concentrated on less-lethal products, and sold leftover inventory from MBA in addition to newly-manufactured items. Trebor filed for bankruptcy in July 1988.
Q: What was PSI?
A: PSI, Protection and Survival International, Inc., was the third company Robert Mainhardt founded, after MBA and Trebor. PSI was founded on September 3, 1991, in an attempt to sell off the remaining inventory of less-lethal devices and Gyrojets from MBA and Trebor. The company was in business for only about one year.
Q: What are “Swarmjets?”
A: Swarmjets are MBA kenetic-energy rockets designed to be fired in salvos to intercept and destroy incoming enemy ballistic missile atomic warheads.
Q: What is the largest Gyrojet?
A: The largest Gyrojet we know of is a 55mm Swarmjet, but only a drawing of this rocket is available. No specimen is known. The largest Gyrojet actually seen is a 40mm cloud-seeding rocket.