Last SHOT Show 2023, I came across Dead Foot Arms and saw their AR-MP9s in person. As one of the resident MP5 fans, I was intrigued. Sure it is not a roller-delayed blowback but the aesthetics are what caught my attention. Since it was designed for the AR-9 platform, the possibilities were endless so I requested to review their upper and they were kind enough to lend one to me. Let’s take a closer look at their MP5-styled AR-MP9 upper.

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Dead Foot Arms AR-MP9 Upper Receiver

Other companies have tried to come out with MP5-styled AR-9 systems. Quarter Circle 10 came out with their YKMF-5 using their MP5 magazine compatible lower. Here is a picture of my YKMF-5. It sort of looks like an MP5 but the handguard is an aluminum extrusion and the barrel is too short. It is in-between a full-size MP5 and MP5K barrel length.

The YKMF-5 is a neat gun with a side charging handle cut into the side of the upper receiver but this is still not MP5 enough. Dead Foot Arms AR-MP9 upper on the other hand is more like an MP5. Here is the Dead Foot Arms upper (top) next to the Quarter Circle 10 (QC10) upper.

Right away you can see some of the iconic MP5 aesthetics on the AR-MP9 upper receiver. It has a fixed front sight tower, forward charging handle and rear diopter sights. I added 416 irons on the QC10 upper in the previous image but it still doesn’t look right. The Dead Foot Arms AR-MP9 upper looks a lot better.

• Weight: 3lb 6oz(With full size BCG)
• Caliber: 9MM
• Barrel Length: 8.3”
• Barrel Thread: 1⁄2-28
• AR9 BCG (Glock, Colt, Endo, and MP5 Compatible)
• Billet Upper Receiver
• Aluminum Components: Hardcoat Anodize – Type III Class 2
• Steel Components: Black Nitride

There is one aspect of the AR-MP9 upper that looks a bit off and that is the rear sight. It sits on a large aluminum block that is bolted to the rear of the upper receiver. The back end of that block overhangs the buffer tower. This is to close off the opening in the upper receiver typically used for a rear charging handle.

There is a soft plastic bushing that slides up into that square slot. This just helps close off the sight block. You slide the bushing down and now the BCG can be removed for cleaning.

The AR-MP9 upper is a direct blowback system and since it uses a forward charging handle, the gas key is shaped differently. It is radiused to interface with the charging handle op-rod. Not sure why it needs to be curved when piston-operated gas keys are flat and this operates similarly just without gas operation.

Dead Foot Arms’ AR-MP9 BCG is cut for MP5 magazines as well as your run-of-the-mill Glock mags, other 9mm pistol magazines like COLT and even the EndoMags by Mean Arms.

The AR-MP9 upper design allows for the use of MP5 handguards. Here is the front of the sight tower. It has the basic shape of an MP5 sight tower but lacks the front sight cap above the barrel. It is not necessary, just an aesthetic difference.

The charging handle is milled aluminum and appears to be threaded onto a steel rod. I would have preferred they used HK MP5 charging handles and used roll pins to install them like real MP5s.

MP5 Handguards

With regards to using MP5 handguards on the AR-MP9 upper, Dead Foot Arms designed their barrel nut to interface the rear of MP5 handguards, like the MP5 trunion. The cocking tube has a notch machined into it so you can attach the handguards. Dead Foot Arms went with a threaded cylinder and hex pan headed screws on either side to hold their handguard in place. I swapped that out for the standard H&K take-down pin.

 

I tried using a KAC MP5 railed handguard on the AR-MP9 upper.

The right side rail encroaches a bit and covers some of the ejection port. I did not actually try shooting this setup for fear that the rail might induce a malfunction and block the ejecting brass.

Shooting The AR-MP9 Upper

I installed the AR-MP9 upper on my QC10 lower receiver. I am using an SB Tactical HBPDW brace with their PCC buffer and spring. I mounted an Aimpoint Pro to the top rail.

Other than the recoil impulse, the AR-MP9 on the QC10 feels like an MP5. The charging handle is a lot of fun to slap in order to get the gun to go into battery. The AR-styled magazine release makes mag changes effortless.

While the QC10 lower was fun, I was curious what else I could use the AR-MP9 upper on. So I put it on my 416 Brownell’s lower and used a Mean Arms EndoMag to feed it.  Below I installed my SureFire forends to the AR-MP9 upper.

I didn’t use a 9mm buffer and spring the first time I tried this setup and had some hammer follow malfunctions. So I tried it again with the proper buffer and did not have any issues.

Final Thoughts On The AR-MP9 Upper

The Dead Foot Arms AR-MP9 upper with full-size BCG retails for $950. I you want their modified BCG to run their folding stock, then you need to add $50. The upper comes with the standard polymer wide handguard, three-lug adapter, and the MP5 style iron sights.

I like the upper since it gives you the looks and charging handle experience of an MP5. You could buy an MP5 clone but with the Dead Foot Arms AR-MP9 upper, you can put it on any AR-15 or AR-9 lower receiver. The only improvement I would like to make would be to build one of these using the CMMG radial delayed system or Mean Arms bearing delayed system. You could possibly use the JP Enterprises roller delayed but that system is very expensive and you might as well buy an MP5 by that point.

If you are looking to add a new look to an AR-9, then the Dead Foot Arms AR-MP9 upper may be something to look into. It is a lot of fun to shoot. For more information check out their website.