Source: inukraine.official on Instagram
Ukrainian troops riding in the back of a pick-up truck or similar vehicle. The soldier taking the video is showing off his anti-drone weapon of choice; a vintage Tula TOZ-66 12-gauge, side-by-side shotgun.
The Tula Arms Plant introduced the TOZ-66 in 1968 and production ran until 1974. Nevertheless, the ruggedness of the design and having been produced in great numbers, the TOZ-66 saw widespread use well after Tula had moved on to more modern designs. As seen here, the TOZ-66 can still be found and this soldier is using it to hunt drones rather than game.
Although the external hammers gives the 8 pound TOZ-66 an antiquated appearance, their use allows the firer to easily see if the shotgun is ready to fire. In the image, the hammers are cocked, meaning the TOZ-66 is ready to fire. Had they been uncocked, the shotgun could be carried loaded with a good measure of safety against accidental discharge. The TOZ-66 has double triggers, allowing the firer to discharge each barrel independently.
The TOZ-66 is a break action shotgun, meaning, to reload, the firer uses the center lever just behind the breech to unlatch the barrels which hinge downward. This downward motion engages an extractor catch which ejects the spent shells. The firer loads new shells then brings the barrels up, engaging the latch. After cocking the hammers, the TOZ-66 is ready to fire. The rate of fire is purely based on how trained the operator is in reloading.