The 700 Nitro was developed in 1988 by Jim Bell and William Feldstein and built by Holland & Holland. Feldstein had tried unsuccessfully to get H&H to build a .600 Nitro Express for him, but they had already ceased production and at that stage was not interested in reviving the project.

There was a reference to a JA Shirley & Co, Gun & Riflemakers operating out of London. The company was incorporated on 25 June 2007 and dissolved on 18 October 2011.