Currently in-game the A-149 Gryphon has a 20MM "Vulcan" Gatling cannon.
It's real-life counterpart, the Saab JAS 39 Grippen is equipped with the Mauser BK-27 27MM revolver cannon.
Unless the current armament choice was on purpose different than it's real-life counterpart, the Gryphon should be changed to have a 27MM cannon.
Specifications can be found in the second link.
If you need more sources or help I'd be happy to oblige :).