- Kel-Tec
- Kershaw
- Keystone Sporting Arms
- Kimber
- Knights Armament Company
- KORE Essentials
- Kriss USA
- Lancer
- LanTac USA LLC
- LBE Unlimited
- Les Baer
- Leupold
- LIVE FIT
- Live Free Armory
- LMT
- Lone Wolf "LWD"
- Lucas Oil
- Luth-AR
- LWRC
- Mace Security International
- Maglula ltd.
- Magnum Research
- MagPod
- Magpul Industries
- Magtech Ammunition
- Marconi Armory
- Marlin
- MasterLock
- Mauser
- MAXSafes
- Mec-Gar
- Meprolight
- Midwest Industries
- Military Systems Group
- Mission First Tactical
- Mossberg
- Namaste Arms
- NCSTAR
- NeoMag
- New Republic
- North American Arms
- North American Rescue
- Noveske
- Odin Works
- OEM
- Owl & Anchor
- Patriot Ordnance Factory "POF"
- Phase 5 Weapon Systems
- Phoenix
- Pioneer Arms