American Made
Buy Machine Shop Direct
Need Assistance? Call us at 425.530.0837
Build Kit 10.5" 5.56 1/7 Upper with 10" Quad Rail Special Edition Upper "Molon Labe" Engraving
On Target With
Savings Of
Original Price $459.99
Sale Price $349.99
Against insurmontable odds, 300 Spartans fought against thousands of attackers.  When told to stand down and drop their weapons they answered "Molon Labe" or in English "Come and Take It" Hardened Arms is proud to present this Deep Engraved Upper AR15 upper receiver with  the words "Molon Labe" to commemerate the fighting spirit that will will not yield.

Our 10.5" Hardened Arms 5.56 upper is one of the most popular configurations we make. The 10.5 inch barrel allows you to keep a carbine gas system which means a smoother running pistol over a 7.5" build. The extra length of the barrel also keeps the muzzle velocity around 2650fps for effective energy on target at medium range. Built with our 4150CMV nitrogen stress relieved barrel blanks these uppers are designed to last a lifetime.

10.5" 5.56mm "Molon Labe" AR-15 Barreled Upper Receiver Assembly Specs:

  • Hardened Arms M4 Feed Ramp Flat Top Receiver
  • Black anodized mil-spec finished upper receiver
  • Feed ramps for increased feeding reliability on barrel and upper
  • Laser etched T-Marked upper receiver
  • 4150CMV Nitrogren Stress Relieved Barrel Steel
  • Black Melonite/QPQ Finish
  • Chambered in 5.56 NATO (will also fire .223 ammo)
  • 6-Groove, 1/7 twist button rifled barrel
  • 10.5" Socom Profile barrel with M4 Extension
  • .750" diameter at gas block
  • 1/2x28 threaded
  • Low profile gas block
  • Barrel dimpled to secure gas block
  • Carbine length gas system
  • A2 flash hider
  • 10" Hardened Arms Quad Rail without endcap
  • "Molon Labe" Deep Engraved Upper
  • Pistol buffer kit
  • Melonited BCG
  • Mil spec Charging handle
  • Lower Parts Kit

Fits any mil-spec AR15 lower receiver.
4150CMV Barrel Steel
Whether starting with our 4150CMV machine gun barrel steel or highly refined 416R stainless steel our barrels are a cut above the rest. Engineered for accuracy and durability they are double nitrogen stress relieved and sodium nitrate coated/melonited (raw stainless steel is polished with melonited extensions). Index pins that lock into the upper receiver are pinned into the barrel through the extension on melonited barrels meaning the extension will never come loose. Machined in house on state of the art CNC equipment we deliver a barrel with every spec carefully controlled for peak performance.
Rail Lock Free Float Handguard
Machining our handguards in house provides us the opportunity to integrate features not found on most rails in the industry. Our rail lock feature, is designed to dovetail around your upper reciever insexing to insure a perfectly aligned rail that extends over the end of the upper reciever enough to do away with the unsightly gap found on lesser quality rail to receiver match ups. Combined with 6061-T6 aluminum with class II type III, hard coat anodized finish to match our uppers, fit and finish are top notch. Hardened Arms has many rail styles to choose from that are both stylish and functional. Our handguard offerings include quad rails, reduced weight rails, ergonomic smooth rails, skinny competition rails and our innovative patented Lumashark(R) illuminated rail with high lumen lights built in. Hardened Arms rails come in a variety of lengths and choices to meet your mission specific needs. .
Attention to detail.
It's the attention to detail that sets Hardened Arms apart. Items such as our machined in house 'Jam Nut' ensure ease of changing muzzle devices and indexing flash hiders while being fully re-useable. Crush washers are a thing of the past as they are single use and can induce stress and cause problems if used improperly. Bull barrels use shims to time your muzzle device without adding to the diameter of the already rigid barrel.

Alignment dimples are also machined into your barrel at the same time the gas port is drilled to provide 100% accurate positioning of your gas block and to keep it securely in place in spite of recoil. We machine our gas blocks and adjustable gas blocks right here from 4150 US barrel steel to give you the strongest and most durable product possible..
Hardened Arms uppers are high end, accurate, head spaced, inspected and test fired prior to shipping. They are built using stringent specs, top quality parts and procedures to ensure maximum reliability and performance.

You are responsible for knowing your state laws regarding barrel lengths, pistol and short barreled rifle restrictions. 20% restocking fees if you cancel anytime after you order or can not take delivery due to state restriction. Dealer programs are available on our website. Two year warranty against manufacturer defects. Finishes will wear with use, no warranties apply to finish wear. Fits any mil-spec AR15 lower receiver.
515 Tucker Ave Friday Harbor, WA 98250 |
Phone: 425-530-0837