Jeff from New Zealand (the owner of Beaver Grease) sent us a photo of a his Wesley Richards .310 Greener (Cadet) with recreated woodwork. The rabbit was taken with a CBE 325-125 cast lead heel bullet over 5gr Unique. I must admit I had never heard of this cartridge before. This is what wikipedia says about it …
The .310 Cadet, also known as the .310 Greener, or the .310 Martini, is a centerfire rifle cartridge, introduced in 1900 by W.W. Greener as a target round for the Martini Cadet rifle. Firing a 120 grain heeled lead projectile at 1200 ft/s the round is similar in performance to the .32-20 Winchester and many rifles may chamber both rounds with some accuracy.
The round was used in cadet rifles in Australia and New Zealand after early 20th-century Defence Acts. In New Zealand, after the start of the Boer War, a cadet corps had been started; by 1901 it was recommended that membership be compulsory. 500 Westley-Richards miniature Martini–Henry rifles were available by October 1902 (Auckland Star), and 5000 by April 1903 (Star). Such rifles gained popularity in Australia, New Zealand and the United States when thousands of Martini Cadet rifles were sold by the Australian government after World War II.
The loads tend to have between 500 – 600 ft/lbs (120gr at 1500 fp/s), which is equivalent energy to a hot +P .45 ACP load. 32-20 Winchester loads, which the Wikipedia article compares it to, it loaded with much less power, 200-250 ft/lbs.