Designed by John Foote (of MAC/Cobray fame), the SSP-91 is a single shot rifle-caliber pistol intended for silhouette competition shooting and handgun hunting. It was introduced by Foote and Ordnance Technology of Stetson, Maine in 1986 as the SSP-86. He made some improvements to the design in 1990, resulting in the improved SSP-91 model available form 1991 until 1993. In 1994, the rights were purchased by Magnum Research, who renamed is the Lone Eagle (to fit their eagle-themed catalog – Desert Eagle, Baby Eagle, etc).
The SSP and Lone Eagle were available in a wide variety of calibers, from .22 Hornet and .223 up to behemoths like .444 Marlin, .358 Winchester, and .30-06. Caliber conversion kits were available, but since they consisted of a whole new barrel and breechblock, the kits cosy about 75% as much as a complete new gun. Production ran until about the year 2000, when Magnum Research discontinued the pistol for poor sales.
One interesting side note is that one of Foote’s subcontractors for SSP part manufacturing, a man named Stratiff, decided to produce his own imported version in 1988. Since nothing on the SSP was patented (the breech system was long since in the public domain), Straitiff build what was basically a copy of the SSP but with an automated cocking system integrated into the breechblock, so that the separate cocking lever was not needed. He marketed this as the “Competitor” pistol, and these can also be found today.