The 226 is a full-sized, service-type pistol chambered for the 919mm Parabellum, .40 S&W, .357 SIG, and .22 Long Rifle. It was developed to use higher capacity, staggered-column magazines in place of the single-column magazines. The 226 was designed for entry into the XM9 Service Pistol Trials that were held by the US Army in 1984 on behalf of the US armed forces to find a replacement for the M1911A1. Only the this and one other pistol satisfactorily completed the trials. Though the M9 was adopted for its lower cost the Navy SEALs, however, chose to adopt the 226 later.
The SG 550 is a selective fire 5.5645mm NATO assault rifle firing from a closed bolt. Emphasis was placed on modularity; the weapon family was to include several variants of the base design, including a compact carbine that would be issued to rear-echelon and support troops, commanding staff, vehicle crews, special operations personnel and paratroopers. Another aim was to reduce the overall weight of the rifle while retaining comparable or improved accuracy.