Thats a commercial rifle stock home nodded I think. the Photosniper was all metal. There were a few variations of the Zenit (pronounced Ginette, like the girl's name) photsniper rig, they had an interesting history.
They were originally made for the old KGB to use for battlefield surveillance, but they were marketed in the West as a kit for those like ornithologists who needed a combination of mobility & stability.
The original camera was a zenit "B" or "E", a Soviet copy of the old Pentax "SV" cameras. The lens was a 300 mm "Tair" semi-auto diaphragm.
Cameras with rifle type stocks are a lot more common than you'd think. I sold these 600, 800 & 1200 mm monsters for a living once & got busted by the British Special Branch because it was so big I was spotted by a helicopter covering a royal procession.
They thought it was some kind of missile launcher
This loks like the 6000mm, the 800 & 1,200 mm are a lot bigger, about 6' long & 14" wide at the front end. We used to say they were the only thing that made a Nikon F Photomic Tn look like a cheap rear lens cap!
