Colt M4 AR-15 Upper Receiver Assembly

Manufactured by Colt
SKU: CTSP63528
MPN: CTSP63528
Manufactured by Colt
4 Reviews

Out of Stock

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This Colt Manufacturing M4 Complete Upper Receiver is built to Mil-Spec dimensions from high quality materials. Forged from 7075-T6 aluminum and hardcoat anodized, this AR-15 upper receiver is the perfect component for your next duty style rifle. It comes with the forward assist and dust cover already assembled and features M4 feed ramps and compatibility with all AR-15 style barrel nuts. The flat top picatinny rail allows you to attach optics and a back-up rear sight. With Colt reliability and an affordable price, you can’t go wrong with this upper receiver.

  • Forged 7075-T6 aluminum
  • Hardcoat anodized black
  • M4 flat top picatinny rail
  • M4 feed ramps
  • Includes dust cover and forward assist

Colt Manufacturing knows firearms. They have been designing them since the first patent made by Samuel Colt in 1836 and they know what it takes to bring quality products to the market for both military and civilians. If you want a firearm proven by time, you can’t go wrong with a Colt.
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AssemblyAssembled Uppers
Feed RampsM4
FinishHardcoat Anodized
Forward AssistAssembled with Forward Assist
Port DoorAssembled with Port Cover
Receiver Material7075-T6 Aluminum
T MarksT-Marked

WARNING: This Product can expose you to chemicals which is known to state of California to cause Cancer and Reproductive Harm. For more information, see

Ratings & Reviews

4 reviews

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New Colt--Cage code + Square forge

by -

Cage code. Square forge. Quality seems good enough. We've gotten to a point where you really need to trust your retailer when buying parts advertised as Colt. I do happen to trust Primary Arms, so no worries, but the fakes are getting good enough that I wouldn't even consider buying from a less credible source. Stay off the forums. Stay away from the gun shows. Lots of fakes going around these days.

COLT Upper

by -

I have ordered a few of these upper receivers from different sites I trust to include Primary Arms. After reviewing all of them, they seem genuine to me and I always trust Primary Arms and have for many years. Things to look for...
<br>-M4 clearly stamped on the front of the receiver
<br>-Square cage code forge strong and doesn't chip away
<br>-Clear Laser T marks painted white on rail
<br>-Already has ejection port and forward assist installed
<br>-Grey dry lube on the interior of the upper to assist with temp control on full auto fire

Colt M4 Receiver As Advertised


Colt M4 receiver arrived in advertised condition & stamped 13629 on port side. I was extremely satisfied with my purchase and plan to purchase several more of these as finances allow. I bought several from another distribuitor and they match this one to the T.

My only regret is that I didn't buy more than one

by -

I wish I had bought more than one because it is near-impossible to find a Colt M16 upper receiver from a truly trusted source.