M4 Military Spec Barreled upper.
M-4 Barreled Upper.

ARM-4 Military 16" Barreled Upper AR-15/M-16

The highest quality, most accurate to a military M-4 barreled upper with specifications that are made for the everyday civilian  today.  This kit contains, a 4150 steel Barrel that is chrome lined with a 1X7 twist rate and made to withstand higher temperatures for sustained rates of fire, Each barrel is Magnafluxed which compared to Magnetic Particle Inspection, is virtually the same( read Faq's for more info).  M-4 Feed ramps, double heat shielded M-4 style hand guards, A-3 Flat top, T marked Upper receiver, F  front sight.  This barreled upper is the closest to the M-4 military rifle anyone can build.  We will follow up with the shorter 14.5" version for SBR rifles soon.  This barreled upper comes fully assembled.

16" ARM-4 Chrome Lined, 4150 steel, 1x7 Twist, F Sight Base, M-4 Feed Ramp barreled upper.
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ARM-4 Military 16" Barreled Upper AR-15/M-16

ARM-4 Military 16" Barreled Upper AR-15/M-16

16" ARM-4 Chrome Lined, 4150 steel, 1x7 Twist, F Sight Base, M-4 Feed Ramps, Magnafluxed barrel, Barreled Upper.

The highest quality, most accurate to military  M-4 Rifle specifications that is made for the everyday civilian  today.  This kit contains, a 4150 steel Barrel that is chrome lined with a 1X7 twist rate and made to withstand higher temperatures for sustained rates of fire, Each barrel is Magnafluxed which compared to Magnetic Particle Inspection, is virtually the same( read Faq's for more info).  M-4 Feed ramps, double heat shielded Oval M-4 style hand guards, A-3 Flat top, T marked Upper receiver, F  front sight, AR-15 Barreled Upper.