"Attachment #3 to GOKO decree #2429ss
October 19th, 1942
Tactical-technical characteristics for a 45 mm SPG
1. Purpose of the SPG
The 45 mm SPG is designed to function as a weapon in tank destroyer regiments and in anti-tank batteries of moto-mechanized units to combat enemy infantry and tanks.
2. Requirements for the SPG armamentThe tank destroyer SPG will use the oscillating part of the 45 mm M-42 model 1942 anti-tank gun. The weapon must satisfy the following requirements:
- Muzzle velocity of 870 m/s with a 1.4 kg armour piercing shell.
- Capability of firing armour piercing, high explosive, and subcaliber ammunition.
- Practical rate of fire of at least 15 RPM in direct fire.
- Gun elevation of at least +15 degrees.
- Gun depression of at least -5 degrees.
- Horizontal arc of at least 30 degrees (15 degrees to each side).
- Horizontal and vertical aiming must be achieved at a speed of at least 1.5 degrees per second.
- The height of the bore axis can be at most 1600 mm.
- The gun must use the AZP sight.
- The gun is serviced by a crew of 3 (including the driver). The fighting compartment must contain folding or removable seats for two crewmen.
- The gun must be reliably fixed in the vertical and horizontal planes during travel.
- The gun must be convenient to load at any elevation or traverse angle.
- The SPG must be armed with two PPSh submachineguns.
- The SPG must carry 90 rounds for the 45 mm cannon and 1000 rounds for the machineguns. The ammunition racks must be reliable and keep the rounds safe in motion. It must be easy to extract the rounds from the rack."