The CRV7, short for “Canadian Rocket Vehicle 7”, is a 2.75-inch (70 mm) folding-fin ground attack rocket produced by Bristol Aerospace in Winnipeg, Manitoba. It was introduced in the early 1970s as an upgraded version of the standard U.S. 2.75-inch air-to-ground rocket. It was the most powerful weapon of its class, the first with enough energy to penetrate standard Warsaw Pact aircraft hangars. The CRV7 remains one of the most powerful air-to-ground attack rockets to this day, and has slowly become the de facto standard for Western-aligned forces outside the United States. Beginning in 2021, 83,303 stored Canadian CRV7s are slated for disposal, having been removed from service from 2005 to 2007. In 2024 the Department of National Defence was considering donating the rockets to Ukraine as military aid to defend against the Russian invasion of Ukraine. An estimated 8,000 rockets have functioning warheads, while the remainder could be used for parts or modification. In September 2024 Canadian defence minister Bill Blair announced Canada would be sending 80,840 rocket motors to Ukraine over the next months, in addition to the 2,100 already shipped, along with 1,300 warheads.

This is the American 70mm (2.75“) M151, a High-Explosive-Fragmentation (HE-Frag), 10-pounder, fin-stabilised, General-Purpose (GP) rocket warhead designed to provide improved aerial artillery capability for the 2.75” FFAR and Hydra 70 rocket system. This rocket is an Air-to-Ground-Rocket (AGR) primarily deployed from rotary-wing and other low-speed aircraft.

It is fitted with the nose-mounted M433 remotely set multi-function Impact (IMP) or Delay (DLY) fuze, which can provide for variable depth penetration of forest canopy, buildings or bunkers, it also has a Super-Quick (SQ) Graze (GRZ) function.

Upon fuze functioning, the main-charge detonates and the warhead shatters into small high-velocity fragments.

This is the American 70mm (2.75“) M229, a High-Explosive-Fragmentation (HE-Frag), fin-stabilised, General-Purpose (GP), 17-pounder, rocket warhead designed to provide improved aerial artillery capability for the 2.75” Hydra 70 rocket system. The M229 warhead is an elongated version of the M151 (10-pounder) warhead and is commonly referred to as the 17-pounder warhead.

This rocket is an Air-to-Ground-Rocket (AGR) primarily deployed from rotary-wing and other low-speed aircraft.

This is the American 70mm (2.75“) M255 and M255A1, an Anti-Personnel (AP), flechette loaded, nose-ejecting, fin-stabilised, rocket warhead designed to provide improved aerial artillery capability for the 2.75” Hydra 70 rocket system. This rocket is an Air-to-Ground-Rocket (AGR) primarily deployed from rotary-wing and other low-speed aircraft.

The M255A1 contains approximately 1179 twenty-eight grain flechettes and three tracers for Air-to-Ground, Ground-to-Air, Ground-to-Ground and Air-to-Ground operations.

Before launch, the capacitor is charged by aircraft power and the desired time (up to 25 seconds) set on M439 fuze via an umbilical cable connector. A metal pusher-plate is located just aft of the flechette cargo stack and is forward of the expulsion-charge assembly. The threaded end of the body is machined internally to accommodate a base-detonating, remote-settable, variable-range fuze.

The primary warhead fuze, M439, is a resistance-capacitance electronic variable time Delay (DLY) fuze. The time DLY is remotely set for the desired functioning distance (time) by charging the circuit from the fire control centre.

This is the American 70mm (2.75“) M257 and M278 Infrared (IR), a flare, nose-ejecting, fin-stabilised, rocket warhead designed to provide helicopters with target illuminating capability from a safe standoff distance in a hostile environment for the 2.75” FFAR and Hydra 70 rocket system that has replaced the earlier M262. The M278 is generally similar to the M257 in operation but emits Infrared (IR) light to illuminate targets to be viewed by night vision equipment.

This rocket is an Air-to-Ground-Rocket (AGR) primarily deployed from rotary-wing and other low-speed aircraft.

The M257 illuminating warhead consists of an ignition system, flare, main parachute, drogue-chute assembly and an integral fuze and DLY assembly. The warhead is enclosed in an aluminium case. The setback actuated fixed time integral fuze provides a stand-off distance of approximately 3,000m.

The arming fuze and DLY assembly are actuated by motor acceleration. Upon rocket launch, the M442 fuze arms upon acceleration (17-G's approximately required).

This is the American 70mm (2.75“) M264, Red-Phosphorus Smoke (RFS), fin-stabilised, rocket warhead designed to provide helicopters with a Smoke (SMK) screening capability from a safe stand-off distance in a hostile environment for the 2.75” Hydra 70 rocket system.

This rocket is an Air-to-Ground-Rocket (AGR) primarily deployed from rotary-wing and other low-speed aircraft.

The M264 SMK warhead can generate screening smoke for up to 5-mins and is activated by a remote set M439 fuze.

The normal SMK composition involved with the earlier M259 rocket was White-Phosphorus (WP), the M264 uses a Red-Phosphorus (RP) based filling of 72 pre-saturated pellets.

This is the American 70mm (2.75“) WDU-4, an Anti-Personnel (AP), flechette loaded, aircraft-fired, nose-ejecting, fin-stabilised, rocket warhead also designated the Mk 149 and the WDU-13 with a setback-armed and diminishing-setback-fired, Base-Detonating (BD) fuze. This rocket is an Air-to-Ground-Rocket (AGR) primarily deployed from rotary-wing and other low-speed aircraft.

When the rocket is fired, the setback-sleeve of the fuze assembly moves towards the rear. At the same time, setback weight in the rotor and housing assembly moves toward the rear, unlocking the rotor. Acceleration causes the eccentrically weighted rotor to turn toward the armed position, which is retarded by escapement while maintaining the setback-sleeve and setback weight in the rear position. At the completion of rotor movement, the detonator is aligned with the Firing-Pin (FP) and the rotor is locked in position by a spring-loaded rotor lock-pin. When acceleration decreases as a result of rocket-motor burnout, the setback-sleeve is pushed forward by its spring.

This is an enlarged version of the WDU-4, an Anti-Personnel (AP), flechette loaded, aircraft-fired, nose-ejecting, fin-stabilised, rocket warhead.

The WTU-5001/B is a practice round, consisting of an 8 lb (3.6 kg) flat-ended soft steel rod encased in a nylon fairing, and later introduced a similar version with a hardened steel rod, the WTU-5001A/B. These rounds matched the ballistics of the M151 for training purposes and were widely used during the development and introduction of the weapon to the Canadian Forces.