C.O.P. C4 Upper Receiver, Full Kit - Anodized Black

Aero Precision C.O.P. C4 - Anodized Black

C.O.P. C4 Upper Receiver, Full Kit - Anodized Black Product Sku: APAR150203F

Out of stock


The C.O.P. C4 (Continuous Optics Platform) features a custom configured integrated upper receiver and handguard system. This extremely rigid design allows for symmetrical or asymmetrical rail platforms to accommodate a multitude of optic requirements. The hand guard system allows for a free-floated barrel giving the operator superior performance and accuracy.

The carbine length C.O.P. (C4) features a handguard that is properly sized to meet up with an A2 Front Sight Block when used with a carbine length gas system. It will cover the gas block when used with pistol length gas system and low profile gas block.

This system uses any standard AR-15 barrel, not a proprietary barrel system. The receiver design also has a fully enclosed dust cover pin which can be removed with the barrel in place.


  • Compatible with Mil - STD AR15 components
  • 7075-T6 forged aluminum construction
  • Extremely rigid user configurable rail system
  • Free-Float handguard rail system
  • AR-15 Standard Barrel Interface, only the barrel nut and wrench are changed (both included)
  • Fully enclosed dust cover pin which can be removed with the barrel in place.
  • Dedicated thumb perch for improved ergonomics when gripping the magwell with the weak hand
  • All kit components made in the USA


  • 2ea 1913 Half Rail
  • 2ea 1913 Rail
  • 1913 Rail with QD
  • 2ea Flat Rail
  • Flat Rail with QD
  • 2ea Quarter Panel
  • T25 Torx Driver
  • 8-32 x 3/8 Screws
  • Barrel Nut
  • Barrel Nut Wrench
  • Factory Installed Dust Cover and Fwd Assist
  • Aero Precision C.O.P. bag roll
  • Installation Manual
Platform AR15
C.O.P. Length C4 (Carbine)
C.O.P. Kit Full Kit
Finish Anodized Black
Material Machined from 7075-T6 forged aluminum
Compatibility Works with standard AR15/M16 components
Weight(s) -
Other N/A

Customer Reviews

4 Item(s)

update from 3/5/2016 Deal of the Century! Review by IntelMerc
Post test fire - more on that later.

Ok so my full build includes this black COP C4 upper kit, basic GI BCG and charging handle, mated to a AP gen 2 lower with a CMMG LPK and ambi safety. Magpul furnature and MBUS sight set. I've now got a Ballistic Advantage Hanson Premium 8.3" .300 BLK barrel. I've also got a basic A2 birdcage flash hider that pokes out from the C4 handguard.

I handloaded .308 148gr FMJ-BT lead core bullets into converted .223-to-.300BLK cases (1.363" COL, seated to 2.165" OAL), charged with 15gr of WIN296 and primed with CCI400. !DUPLICATE AT YOUR OWN RISK!

Complete cycle of operation is perfect, down to the last round and a bolt fully locked to the rear.

Aero Precision COP C4 upper and Gen 2 lower fit and finish: EXCELLENT

Build accuracy: One ragged hole at 25 yards with iron sights, unsupported, with my hand loads. What more can I say?

You can't go wrong with Aero Precision C4 / Gen2 combo and a Ballistic Advantage Hanson barrel! (Posted on 3/20/2016)
Deal of the century! Review by IntelMerc
I actually found a new in box Black C4 minimalist kit from a different source for $250! I don't even see this version listed here, but maybe it's an older version. Regardless, this monoblock upper is MFn BEAUTIFUL!

I matched the upper to an AP Gen 2 lower, CMMG parts kit and ambi safety, Magpul grip, trigger guard, and MBUS sight set, pistol buffer kit, .300 Blackout Ballistic Advantage Performance 10" 1:7 barrel, and a SilencerCo SpecWar flash hider. Riding on top I have an Eotech 552.

If I didn't know better I'd say it was a laser blaster!

Function check SAT.
Dummy round cycle of operation SAT.

Test fire tomorrow! (Posted on 3/5/2016)
Good with a tight fit Review by Davin
I built one of these onto a aero freedom lower and the fit is very tight, matches up perfectly and to be honest I'm happy this was my first upper as the barrel was a lot easier then I expected. The Adams arms piston was a bit weird to put in but worked out in the end (Posted on 11/21/2015)
Expensive but AMAZING Review by John
BEST upper I've seen ever. Slim profile in my hands and configurable. Great quality with the exception of the proprietary barrel nut wrench. If you don't use it VERY VERY VERY VERY carefully it'll break EASILY. I went through three of them before I figured it out, but I am a bit over eager admittedly. On the high priced side even for an upper and hand guard but you get what you pay for. Also expect to have to shave a bit of material off to fit onto non-aero lowers. I believe this is due to aero's exacting standards and not a fault of theirs. Love it though- bar none best upper I've ever handled. (Posted on 10/7/2015)

4 Item(s)

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