Faxon Firearms Integral Series barrel 15A58M16NPQ-IMDF is a 5.56 NATO AR-15 barrel with a Pencil contour and an integrally machined slim A2-style flash hider. The rifled section is 14.5 inches; the integral device brings overall length to 16 inches so a rifle-length build does not require pin-and-weld work.

Faxon machines the barrel in-house from 4150 CMV steel, button-rifles it 1:8, and finishes it salt-bath nitride inside and out. The Pencil profile is Faxon's lightest contour and is meant to put mass rearward. The gas system is mid-length on a .625-inch journal 1.1 inches long. The extension is M4; the crown is an 11-degree target crown. Approximate weight is 1.19 lb.

The flash hider cannot be removed or swapped; it is part of the barrel for alignment and the 16-inch overall length. A gas block and barrel nut can still pass over the slim integral device. Each barrel is stress-relieved, air-gauge tested, magnetic-particle inspected, and headspace verified.

• Manufacturer: Faxon Firearms — Integral Series 15A58M16NPQ-IMDF, UPC 816341025110
• Caliber / twist: 5.56 NATO; button-rifled 1:8
• Length: 14.5 in rifled / 16 in OAL with integral slim A2 flash hider
• Gas: mid-length; .625 in journal x 1.1 in; M4 extension
• Material / finish / weight: 4150 CMV; salt-bath nitride; ~1.19 lb