The saga of how the original Stemple 76/45 became the Stemple Takedown Gun is a fantastic story of engineering design choices.

Essentially, John Stemple began by building a rather crude copy of the Swedish K in .45 ACP in the mid 1980s, called the Stemple 76/45. He produced and registered 2,000 transferrable receivers for the gun (pre-1986), but only built them slowly, a few at a time. In the late 1980s he faced criminal charges from ATF, and transferred the receivers to a friend while he (successfully) fought the charges. When he went to get the receivers back, his friend refused, and the two entered into a nearly decade-long legal battle over them.

By the time Stemple eventually won the case, he recovered about 900 transferrable tubes. By this time (circa 2000) these tube receivers were much more valuable than when he first made them, as the machine gun registry was closed in 1986 and new ones can no longer be made. At this point, Stemple reached out to Brian Poling (BRP Corp) to act as a subcontractor to make the parts for the Stemple 76/45. But Poling had a better idea...

Poling's thought was to instead design a new gun that would be much more desirable as a recreational gun than the 76/45. He envisioned something controllable, low recoil, and using large drum magazines. Such a gun would be a lot more fun at the range than the MACs and Uzis that tended to dominate the submachine gun market at the time. In addition, Poling's gun would be designed specifically to protect the irreplaceable registered receiver tubes from wear or damage. The result was the STG-76 - the Stemple Takedown Gun.

In order to remain legal, the STG-76 had to leave the original 76/45 receiver tube cutouts unmodified, so as not to change the configuration of the receiver itself. Poling designed a replaceable internal trunnion and slip-over magazine well, allowing multiple different calibers and magazine configurations. The internals were closely based on the Finnish kp31 Suomi, for which parts kits became readily available in the early 2000s. This also facilitated the use of Suomi 71-round drum magazines. The original STF-76 design also included a bipod for easy shooting, and a grip and stock from an HK91 or CETME Model C for comfortable handling (instead of the terrible metal strut stocks common to most budget SMGs).

Several other interesting configurations would follow (stay tuned for those videos), and the guns remain available brand new to this day. The original supply of receivers is sufficient for production until about 2023...