AR-15 Quad Rail Buyer’s Guide: Quad Rail Length
Posted by Monstrum on Jan 31st 2019
Quad Rail Length: Carbine Length, Mid Length, or Rifle Length?
Quad rail handguards typically come in three standard sizes: carbine length, mid length, and rifle length. We now carry a new size called extended length. The size of the quad rail handguard you want to use will depend on the length of the gas tube system on your rifle. The length of your gas tube system should be clearly labeled by the manufacturer of your rifle or AR-15 upper. Otherwise you can check by measuring the distance between the front of the AR-15 lower receiver and the rear of the front sight/gas block.
- For carbine length AR-15’s, the distance between the receiver and front sight/gas block is approximately 7 inches.
- For mid length AR-15’s, the distance between the receiver and front sight/gas block is approximately 9 inches.
- For rifle length AR-15’s, the distance between the receiver and front sight/gas block is approximately 12 inches.
- For extended length AR-15’s, the distance between the receiver and front sight/gas block is approximately 15 inches.
The length of the quad rail handguard itself may be a bit shorter than this to accommodate the delta ring and will also vary depending on the form factor. But for the most part: Quad rails of a designated length(carbine, mid, or rifle length) will fit the standard corresponding length rifle