In reply - I started to collect rifles chambered for .303 many years ago and along the way developed an extra interest in Ross rifles and commercial BSA rifles.
These represent what I have accumulated so far just going to auctions and shows in Melbourne.
The top four are military pattern target rifles - Magazine Lee Metford - Charger loading Lee Metford and Enfield (Territorial Pattern) and an SMLE.
Followed by No. 1 and 2 pattern sporting rifles and a No. 4 pattern carbine.
The last two are No. 1 and 2 pattern carbines (for officers' use) - BSA did not get a contract to
produce the Cavalry carbine but decided to offer two slightly different carbines to the officer class who until the first world war were required to provide their own kit.
For a rifle to qualify it had to use the standard ammunition (.303) and to be sighted to 1000 yards.
Not common here in Australia - I have seen 3 No.1 and one 2 and no more for 20 years.