This is a WW1 stand for mounting a .303 rifle, to train soldiers in shooting.
This device consists of two parts;
1. Top part has an adjustable 'arm' . At the end of each arm is a leather covered 'U' section. Under the arm is a large threaded rod and knurled knob, this is to adjust elevation. At the center of the arm is a pivot that can lock into position. This top section is mounted on a tripod, it can be removed.
2. This is a steel tripod made out of 'T' section steel. There are fixed cross braces about 40 cm fom bottom. The top has a tube section within which the upper arm mounts.
Inscriptions & markings
Marked on one leg is "XXI". Believed to be from 21st Bn. AIF. on the top of that leg is a very small arrow head.