Foxtrot Mike Products Complete Upper 16" .45 ACP for Glock Style Receivers - 15" M-LOK Rail

Manufactured by Foxtrot Mike Products
SKU: FM45-16UR
MPN: FM45-16UR
Manufactured by Foxtrot Mike Products
4 Reviews

Out of Stock

NOTE: Limit 1 per household. Quantities exceeding 1 will not allow checkout.



This Foxtrot Mike AR-15 pistol caliber carbine complete upper receiver comes with a huge assortment of features and improvements that can’t be had if you build yours from the ground up. With the FM products .45 ACP AR upper receiver, you get the functionality of a non-reciprocating side charging handle instead of the traditional T-handle. Now you can charge the rifle while still on target without having to lower it from your shoulder. The upper receiver and handguard are a monolithic design with a proprietary lock system that ensures the rail won’t loosen over time. The slim free float handguard features the popular M-LOK system, so you can attach lights, rail sections, or other accessories. Underneath the 15” M-LOK handguard is a 16” 4150 chromoly barrel that has a 1:16 twist rate for stabilizing the .45 ACP projectile. This barrel comes with a FM products muzzle brake to help tame the recoil of the blow back .45 system. Why build a .45 ACP AR-15 from the ground up when you can get a head start with this complete upper from Fox Trot Mike Products.

  • Non-reciprocating fixed forward charging handle
  • Left or right side charging
  • 16” 4150 chrome moly barrel
  • 15” monolithic free float handguard
  • M-Lok attachment points
  • Continuous picatinny top rail
  • .45 ACP bolt carrier group included
  • FM products muzzle brake with 5/8x24” threads
  • Compatible with Glock magazines

The FM products 45 caliber upper receiver is designed to be used with the FM pistol caliber lower receivers as well as other .45 Glock lower receivers that use Glock magazines. Build the ultimate pistol caliber carbine for the range or home defense with the Foxtrot Mike complete upper receiver assembly.

Feature rich, high-quality, and affordable, Foxtrot Mike Products offer cutting edge solutions utilizing the highest quality materials and manufacturing processes available.

Manufacturers Note: FM Products does not support the following items, using these may void the lifetime warranty associated with our uppers;
1) FM Products does not support Aluminum Cased ammo.  Blow backs have a much higher pressure spike in the chamber than a handgun.  Using Aluminum cased ammo in a blow back PCC is dangerous and will void the lifetime warranty of an FM Products Upper Receiver.
2) FM Products does not support import magazines besides OEM Glock magazines.  We recommend Magpul, OEM Glock and ETS magazines only.
3) FM Products does not support Spikes Glock style lower receivers.  The LRBHO requires consumers to modify the FM Products upper, to make egress for the Spikes LRBHO.  The FM Products upper is cut to the Colt spec, therefore we have no plans to deviate from that.  Modifying your FM Products Upper to accommodate a Spikes Tactical Glock style lower will void the lifetime warranty on our PCC Uppers.   
4) We only recommend Sylvan magwell adapters, as they require no modifications or adjustments to work properly.   FM Products does not support Stern Magwell Adapters as they require regular adjustments to work properly. 
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AssemblyComplete Assemblies
Barrel Length16
Barrel Material4150 Chrome Moly Vanadium Steel
BrandFoxtrot Mike Products
Caliber Gauge.45 ACP
Gas System LengthBlowback
Gas System TypeBlowback
Handguard15 in M-LOK Rail
Muzzle DeviceMuzzle Brake
Twist Rate1:16

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


Well Constructed but issues to consider before buying

by -

This is a well built upper, with a unique design for side charging. It is also very light weight with a great handguard. Unfortunately, I had some problems with it. First it doesn't appear to work with with a New Frontier Lower - I've had both first round feeding issues, and may failures to feed that I just can't seem to get 100%. Also the charging handle on the side has a couple issues. First, it appears to have some friction (even after clean/lube) that just won't go away and tends to create issues with mis-feeds on the first round, and they also left a sharp edge of rail next to it - it will eventually cut you. After all that I'm giving up on it, but maybe someone with a different lower will have better luck, and taking the sharp rail edge off with a dremel will prevent it from cutting you so you can fix it pretty easily. So I'm giving it 2 stars still, I'd give it 3 but Foxtrot Mike did not reply to 2 of my inquiries via the web so don't count on them for support either.

Soft recoil with sub sonic ammo, runs like a champ


I got this and used a magazine block and it ran great, shooting sub sonic is super fun and the recoil is soft, been shooting steel case and blazer and havent had any issues. Like the handle because I can put it on the right side cuz Im a lefty. Great product, my friends really like shooting it too.

failure to feed problem

by -

I got this upper and matched it with a FM lower. After about one hundred rounds, I am having feeding problems every one to three rounds. It seems to not strip the round off flush to the bolt face and jams up against the barrel throat.

Great gun but not right out of the box....


I have a love hate relationship with this FM upper and lower. I have owned this weapon for 3 months now and I am finally getting it to cycle reliably. Using glock mags, it would fail to feed every other shot with the round stovepiped between the chamber and bolt carrier. I also noticed flecks of brass around the chamber. My magazine followers were also getting scored. My bolt carrier had a machine spur on the bottom of the bolt face that was scratching the brass and magazine... no wonder it would not feed! Called FM ....they said mail the upper back. They put a new barrel and bolt carrier in. the weapon now runs like a machine. It is very accurate and a lot of fun to shoot now that it reliably functions. In summary... not sure I would buy the 45 again. I hope I have the bugs worked out. But...for almost 700 bucks...I don’t think it is too much to ask for a fully functioning weapon out of the box. Buyer beware. FM has been great to work with.. but...