across the lands of the rifling .458”-.464”.
The first trials pattern P1871 Martini Henry rifle were manufactured the Royal Small Arms factory at Enfield lock, of which over 200 examples were made. The main result of the field testing was that a revision was to be made to the chamber and the powder load increased to achieve a satisfactory velocity at 1300 feet per second (400m/ps). Cartridge manufacturer, Eley, had been independently experimenting with a bottle shaped Boxer round. The increased load and shorter chamber requirement of this new technology, gave the Martini significant accuracy and velocity benefits up to 1360 fps. The new chamber was designated in .577”/.450” calibre. The cartridge was to contain 85 grains of Curtis and Harvey No6 black powder and measured 3.15”overall when loaded. The bullet was a 480 grain unjacketed lead slug, measuring .450” and paper patched to .458”. Behind the bullet a 3mm beeswax wad, with a wool filler .
The range and sighting of the Martini henry was via an Incremental rear sight. 50 yard, sighted from the block, 100-400 yards via a ramp and 500-1500 yards via a sliding ladder sight. At 500 yards the bullet flew through an arc of over eight feet. The rifle was very accurate, a trained marksman could expect to hit a 24” (600mm) target at 500 yards, and the round was lethal at 1000 yards.
Here we see the two variants of the Rear sight, to the right the early Mk1 pattern, shallow notch. Note the groove at the axis point to allow 50 yard sighting.
To The left is the Mk2-Mk4 ladder sight, note the deeper notch and lines for windage allowance. The graduations from 500-1200 yards are visible