The men were barbaric and warlike in appearance. Over their backs hung long-barreled rifles, with two yard-length, curved prongs attached by a swivel to the stock near the muzzle. These prongs swung down to be used as a rifle-rest when firing from a prone or seated position (p.34).
Source of Descriptive Information
Forman, H. (1936). Through Forbidden Tibet. London: Jarrolds