Development was started by Ernst Leitz Canada (ELCAN) in the 1980s when the Canadian military made the decision to make an optical sight the standard for the then new C7 and C8 rifles. The DCIEM (Defence and Civil Institute of Environmental Medicine) established that a 3.5x scope was the optimal magnification for the new small arms sight. Additional requirments included being able to be dropped 5ft while attached to a weapon, and immersion in up to ten meters of water (Bartocci, 2004).
The new scope in development at ELCAN now called the Leitz WildCat (Wild due to the then recent merger between Leitz and Wild Heerbrugg, Cat for Combat Acquisitioning and Targeting) began testing with Canadian Armed Forces in the lates 1980s. In 1991 an upgraded 3.4x version of the scope now called the ELCAN 3.4x Optical Sight was adopted by the Canadian military as the C79 (NSN 1240-21-906-8151) and 65,000 units were purchased (Bartocci, 2004).
Prior the final adoption by Canada, Colt had selected the new ELCAN scope for use with its ACR (Advanced Combat Rifle) submission to the US military in 1990. While the ACR program failed to result in an adopted rifle, in 1999 the United States placed an order for nearly 30,000 scopes for use on M240 and M249 machine guns. The US scopes designated M145 (NSN 1240-01-411-6350) included minor differences from their Canadian counterparts. Follow up contracts would be made for additional scopes including versions for the M4 carbine (Bartocci, 2004).
Bartocci, C. (2004). Black Rifle II. Collector grade Publications.