Foxtrot Mike Products 5" Complete 9mm AR-15 Upper for Glock Style Receivers - Blast Diffuser

the "blast diffuser looks completely different on the upper that I received and the threads are aboslutely not 1/2x36. They are 1/2x28 and no i have an adapter that doesn't fit. I went searching for the upper that i did receive and found it. on Mike Foxtrot's website: https://store.fm-products.com/products/fm-products-5397-d3023ecd-0345-4ce9-bca5-4453b40587b8.

Coupled this upper with CBC's dedicated Glock Lower, and selected the buffer/spring as recommended by Blowback9. Used OEM and Magpul magazines. This thing runs like a charm, and eats both IMI Hollow Points and FMJ. Note: Tune the ejector to not let the magazine over-insert.

For first time builders/ shooters, this is a great AR9 upper to get started with. Barrel feed, BCG, CH, muzzle device, all great.
For anyone else that builds weapons...
The biggest issue is that you cannot mod the upper. Yes you can swap the barrel out... but unless you swap to barrel specs that FMP already provides, there is NO handguard that works. Maybe Bowden Tactical because it looks to seat flush but the proprietary anti rotation rail built into the handguard is unique to FMP. And most handguards being built with anti rotation tabs now will not seat the upper. Very disappointing for any midlength builds around 7".

I love Foxtrot Mike products. Their complete upper of course matched up great with their complete lower. But now after a long wait on a particular agency to approve a suppressor and then getting it shipped, I have found that FM 9mm barrels can't accommodate a suppressor. The muzzle threads are NOT MILSPEC and so far I have not found a single brand of suppressor that makes / sells an adaptor since the muzzle threads are 1/2" x 36 and not the standard 1/2" x 28!!
So...I am now trying to sell both FM complete uppers and going to purchase MILSPEC 9mm uppers that WILL accommodate the suppressor I have paid dearly for. Only other option is buying two new barrels, but am waiting to hear from Foxtrot Mile as to whether or not the upper receiver is MILSPEC and can accept non-FM barrels. Live and learn, but it NEEDS TO BE IN THE DESCRIPTION of this product that they are not MILSPEC threads.

Note: It was good to speak to you about an adapter for the FM barrel and provide you with a source for that. Please let us know if there is anything else we may help you with.

Fast delivery Got mine and put it on AR15 lower 1st Then I bought a 9 mm Foxtrot lower receiver love it Had about 1 years now Had no jam Would recommend this it's loud though Can't wait to get a silencer for it...

Purchased this a while back to complete my FM9 Glock full lower and just shot it a week ago. Works great and no FTF or jams. Great as a defense weapon where sound is not a factor. *** Adding a "hand stop" is a must. Big hands can slip right off the front of the handguard and get burned by diffuser blast! Almost saw a loss of finger that day. Only other "con" is that you cannot add a suppressor to the weapon without changing the handguard and barrel. The interior of the handguard will not accommodate a suppressor or suppressor adapter being screwed onto the very short barrel. Will be purchasing a different complete upper and selling this one. But if you are not going to run a can on it, it is great. Good quality and great tolerances.

I told myself I didn't need this for over a year, I've got plenty of 9mm pistols so why an AR9? Finally bought this along with FM9 Premium upper and don't regret it one bit! Bought and used 2ea of the Glock 33/rd and Magpul 27/rd mags and had no issues with either. Shot 124 gr ball, 124 gr HP and 147 gr HP from S&B, PMC and Sig, everything functioned perfectly including the LRHO feature. This is a ton of fun (more than I anticipated, lol) and my son and I went through 300 rds before we knew it.

Running it on a Colt Style CMMG lower with a Tailhook Brace and Duramag magazines. About 300 rounds downrange with zero issues of any kind. A bit more recoil than I was expecting but not bad. Accuracy seems very good so far using irons. Just put a Red Dot on it and will shoot for groups soon.
So far it is Fun, Fun, Fun

I had an existing AR-15 Pistol lower that I wanted to be able to run 9mm in. I also didn't want to bolt down a mag well adapter. The following items along with the FM9 upper run well for me and are a joy to shoot.
- Endomag insert into a Magpul P-Mag.
- Expo Arms 9mm Extended Carbine Buffer - 8 oz

I bought this a few months back and have ran almost 500 rounds through it and have only had 2 jams. I am using this upper reciver on my standard ar15 pistol lower reciever with meanarm's 9mm endo mags, angstadt arms ar9 buffer and spring, also I replaced the bcg with a failzero ar9 bcg, also put a elftmann ar9 drop in trigger and it's been running flawlessly. I really like this set up! I just recently bought a colt mag well adapter as I heard foxtrot mike uppers can run glock or colt mags depending on the bcg and the fail zero bcg works for both glock and colt! I'll update this review after I run it with the colt adapter. But so far I love this upper reciver. Pew pew!