- FAB Defense
- FailZero
- Federal
- Fiocchi
- FMK Firearms
- FN America
- Fortis Manufacturing, Inc.
- Four Peaks
- Franklin Armory
- Freedom Ordnance
- FrogLube
- Frontier Cartridge
- FSDC
- G2 Research
- Geissele Automatics
- German Sports Guns
- Ghost Inc
- Glock
- Grayguns
- Great Lakes Ammunition
- Grey Ghost Precision
- Grind Hard
- Gunslinger Armory
- Guntec
- Harris Engineering
- Heckler & Koch "HK"
- Henry Repeating Arms
- Hera USA
- Heritage Rough Rider
- Hexmag
- Hi-Point
- High Speed Gear
- Hiperfire
- HKS
- Holosun Technologies
- Hoppe's
- Hornady
- Howard Leight
- INFORCE
- IWI
- Juggernaut Tactical
- Just Right Carbines
- KABAR
- Kagwerks
- Kahr Arms
- Kalashnikov
- Kalikey
- KAOS Concealment
- KCI
- Kel-Tec