The Guntec USA AR-15 Ultimate Rifle Kit Handguard is 15" that answer is being corrected.
The Guntec USA AR-15 Ultimate Rifle Kit has certain small components that would work such as the pistol grip and buffer tube, however, other components like the handguard, bolt catch, magazine catch, pivot pin, takedown pin and more would not be compatible.
The Guntec USA AR-15 Ultimate Rifle Kit handguard is 15" long.
I have an AR 15 5.56 springfield saint victor and I would like to know if this kit fits without problems and if the handgard is 15" OR 12". THANK YOU.
All of the items in this kit, with the exception of the muzzle device, will be compatible with a .300 Blackout. The included muzzle device if for .223/5.56 and it will be too small for a .300 Blackout.