The .505 Gibbs was introduced in 1911 as a proprietary cartridge by Gibbs for use in Mauser-type bolt-action magazine rifles. Rifles in .505 Gibbs were imported by American dealers and used to a limited extent here. A few custom-built rifles chambered for the .505 were also turned out by American
gun makers. Most of these big-bore Nitro cartridges were developed around 1910, and this one was still available until quite recently. Bullets and cases are still available, and a few Ruger M77 Expresses have been rebarreled to this round.

The .505 is slightly less powerful than the .500 Jeffery, but both have an edge over the .458 Winchester. The .505 Gibbs is considered adequate for anything in Africa and has a good reputation against elephant, buffalo, and lion. Barnes makes bullets specifically designed for this cartridge.

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