The .275 No 2 Magnum, also known as the 7mm Rigby Magnum Flanged and the .275 No 2 Rigby, is an obsolete centerfire rifle cartridge developed by John Rigby & Company in 1927.
The .275 No 2 Magnum is a rimmed cartridge intended for use in double rifles. Rigby introduced the .275 No 2 Magnum by necking down the .375 Flanged Nitro Express, it was still available in the early 1960s. The .275 No 2 Magnum's performance is comparable to the .275 Rigby.
As is common with cartridges for double rifles, due to the need to regulate the two barrels to the same point of aim, the .275 No 2 Magnum was offered in one loading, firing a bullet with a listed speed of .
In his African Rifles and Cartridges, John "Pondoro" Taylor rated the .275 No 2 Magnum as his favourite of all the small bore cartridges.