Foxtrot Mike FM (Fail Much) 15 Gen 2 - I Wanted a PDW
Updated
3 months ago
Good morning, everyone, this is John with gun.deals, today we're going to be taking a look at something that is very interesting, conceptually, this is the Foxtrot Mike Gen 2 AR-15 upper receivers. These use a captured recoil system entirely inside of the upper receiver so you actually don't need the buffer tube on an AR-15 at all.
Full disclosure on the Foxtrot Mike Gen 2 upper receiver is that I don't have any relationship with Foxtrot Mike whatsoever, I do have access to distributor pricing on their products through a third party. However, they were all out of stock so I actually paid my own money for this, I paid full retail price on an open box model, and I got this 9-inch upper receiver for I think $360, which is pretty darn cheap for what is a novel-ish design and certainly not standard AR-15, especially considering some of the stuff that it comes with.
Getting into the basics of this little guy, as I mentioned earlier the entire recoil system is captured within the upper receiver, which is on paper a very cool feature and something that does have a couple of advantages, so with our forward charging handle here we can actuate the system and it is entirely contained within the upper receiver, so you don't need a buffer tube, meaning that you can use a lower receiver that has a Picatinny and plate, and in fact the Foxtrot Mike products Gen 2 upper receiver does in fact come with a Picatinny adapter for a standard AR-15 lower receiver. This is a very nice value ad as I think the cheapest aftermarket option is 40 or $50, so that saves you $50 if you want to run like a side-folding stock or something like that.
Getting into some other specifics of it, before we get into how it operates and how it doesn't operate, is this is a 9-inch barrel with a pistol length gas system, it is still a DI AR-15, so this is not a piston system, they couldn't fit a piston with the charging handle assembly all of that in the same space, it's just too tight to do that, so you do have a standard-ish AR-15 gas block. The barrel itself is a very, very lightweight profile, it is 9 inches, 4150 chrome moly vanadium steel, 223 Wylde chambering with a 1:8 twist, which is perfectly fine, we'll get into accuracy later on, some loads performed very well, and others kind of mediocre.
The barrel is a very lightweight profile, I believe it is using a .625-inch gas block. Talking about the gas block it is a very diminutive gas block, there are no set screws, but it is double pinned in place. Double pinning on a gas block is somewhat redundant, once you have one pin it's pretty much done at that point, but since there are no set screws on it that I can see, two pins is perfectly fine, a little bit overkill, but not a bad thing by any means. The handguard itself is 8 inches long, seven-sided M-LOK, fairly nice, there is a very interesting barrel nut assembly underneath.
The way that the handguard mounts is you have these two large crossbolts kind of just stickingout of one side of the handguard that clamp it down to the barrel nut, but they also channel into the barrel nut, so that the handguard cannot move forward, and on top of that there is a notch cut into the top of the upper receiver so that the handguard and the upper receiver actually made up perfectly. These are not standard AR-15 barrel nuts, handguards or upper receivers. As you might be able to tell, when it's on a lower receiver it is about a half inch taller than a standard AR-15 lower receiver, and that is to fit the recoil assembly cuz it is a little bit taller, and when we get to looking at the bolt carrier group it's a fairly interesting design.
Moving back from there to the upper receiver, it is a very sturdy design, it looks to be Billet, no forward assist, it does have a bolted-on brass deflector and a mil-spec dust cover. Other than that it is not standard mil-spec because it does have a very interesting recoil system going on in the inside. Let's go ahead and get into the back end of the Foxtrot Mike Gen 2. On the inside we have our chopped in half bolt carrier group with a second piece bolted onto the top via the gas key to add some stability inside of the upper receiver, and to also add some weight, because when you remove weight from the bolt carrier group you are going to increase its velocity. AR-15s are very, very timing dependent, so whenever you're messing with one of those timings you got to compensate somewhere else. So, it is still a lighter bolt carrier group than a standard mils- spec bolt carrier group, but it is not quite as bad as it looks, it's not a straight 50% reduction in mass or weight. The entire recoil assembly consists of a guide rod and two springs that overlap each other, this is going to be where some of the more major complaints come from.
Because it is not using an AR-15 style buffer tube you do not get the advantage of adjustable buffers and springs, you have these two overlapping small springs trying to do the job of a carbine spring and buffer, and they don't really get it done, and the gun does seem to be over gassed or under sprung, whichever one you want to say. Before we get to reliability we should talk about the charging handle because the charging handle is another defining characteristic of the Foxtrot Mike Gen2 upper receiver, so we can lock it back to the rear via this ambidextrous lower, and that right there is going to be one of the problems, especially when it gets cold or when it's not just dripping with lubrication those two overlapping springs in the recoil assembly really enjoy getting bound up on each other for no reason, meaning that it's somewhat difficult to operate, especially when it gets cold.
Today, when I was shooting it, it was 25° out or so, it was lubricated before firing fresh out-of-the-box, and there were some slight issues, but before we get into that, the charging handle is adjustable, you have technically four different positions, you can have up on the right, down on the right, because you can flip it to the down position or you can have it on the left hand side as well. On an AR-15 I use the charging handle once per day if it doesn't have any malfunctions, so I just want it out of the way so it is up and to the left, meaning that it doesn't touch me whatsoever, if I ever need to actuate it usually it should be one at the beginning of the day, charge the gun, and then in theory you should be good for the rest of the day.
I should also mention that the charging handle itself does not work as a forward assist, it does however have a spring return on it so it will sometimes go forward, not always, though I don't know why they just didn't include a slightly stronger spring to make sure that it always go forward, if you angle it down it'll actually go forward cuz it is sprung, and there I just locked it back, but you can tell the dual internal recoil springs that they have, they're just not quite working properly, and they do get bound up, so even though the charging handle is nice and ergonomic you have to really yank on it or try and go as fast as possible so that it doesn't have time to bind up, and you can actually lock it to the rear or charge it if you need to.
Before we get into reliability I should mention that this is the 9-inch version with a pistol length gas tube, so I'm not sure if they're using extra power springs in the back to kind of adjust for that very short gas system because they do make this in I believe a 115 carbine 137 mid, and then a 16-inch mid as well, so I'm not sure if they're tuning their springs to be extra powerful on the 9-inch version. However, we had probably about a half dozen different stoppages, I did suppress this with a YHM Resonator K, which is a high back pressure can, and unfortunately the system is over gassed from the factory and there's really nothing you can do to tune it, there doesn't appear to be an adjustable gas block, you can't swap out the springs to something else, and it's not utilizing an AR-15 buffer tube so you can't simply switch to a stronger spring and heavier buffer, and even when unsuppressed it was a very, very violently over gassed system. With Tula 55 grain you were getting very, very forward ejection, you can't compare ejection pattern on this shell deflector versus like a standard AR-15 shell deflector on a mil-spec upper receiver because just by changing the angle of the shell deflector you're going to change your ejection pattern, so you can't just take it for a one-one comparison.
However, even with 55 grain Tula, on the coldest day of the year, it was very, very over gassed, then switching to 55 grain-ish M193 not quite arms core ammunition, very, very punchy, and the last ammo that I tested was full power Winchester M855, and that was easily the worst recoil I have ever felt on a 5.56, it's punchy, it moves you around a little bit, like you would not expect for a 5.56, and keep in mind that I've shot quite a bit out of a 5-inck K tactical upper receiver with a micro length gas system, and that was actually a comparably very, very soft shooting upper receiver compared to this monstrosity.
With it being that over gassed without a suppressor, when I added a suppressor to the system it became so overdriven that it was outrunning the magazines and so it would not cycle at a couple points, and so I had to take off the suppressor for the rest of shooting, which is a little unfortunate because 9-inch 5.56 does have a lot of blast, and even without a suppressor, with the hotter ammunition, on a very, very cold day, the gun was looped, I was still having feeding issues with it, and unfortunately for Foxtrot Mike there is a very simple solution to this, either just make the gas port size smaller to begin with, keep in mind I'm using the weakest ammunition on the coldest day of the year, and it's still violently over gassed, even with just cheap steel case ammunition, and there's no way to adjust it down. If they had either just made the gas port smaller or made some way for the end user to adjust the gas with just a simple adjustable gas block or some other mechanism there in, not only would it make it a more pleasant system to shoot and more useful as you could use it in conjunction with a non-flow through suppressor, but would also make it more reliable as well.
In my opinion there's really not a good reason for agun like this to ship like this from thefactory when you can just manufacture the gas port a little bit smaller and that probably should have been figured out in testing and development. We should at least talk about accuracy out of this, this is a 9-inch 5.56 barrel or 223 Wylde barrel I should say, and we actually got some pretty decent accuracy. Starting off with that Winchester M855 at 50 yards it put up about an inch and a half to 2-inch group, which is perfectly fine for M855 that is not known for being a particularly accurate load, then moving on to 75 grain Hornady performance, that shot also at about 2 inches, which is pretty bad for a really good Match ammo, however, we followed that up with some Sig Marksman 77 grain OTM and that shot four rounds into the exact same hole.
The barrel is capable of good accuracy when you find a load that it really likes, that Sig Marksman ammo has been fantastic so far and everything that I put it through so that seems to really like this short barrel, and it is nice to see a group that good and that is actually why we have this huge 1-10 LPVO on here, even though I tested it with a red dot is this one here was what I used for the accuracy portion of the review. It is capable of good accuracy, and with basic Ball ammunition gets acceptable accuracy. My intended use case for this was essentially a folded PDW plus bag gun basically so I will personally find a way to remedy the issues with the gas system, make it a little bit softer to shoot, it will end up with a folding Picatinny stock and suppressed as well, and even if Foxtrot Mike can't do it I will find a way to make this run reliably and run the way that I want it to, but that will be for a future review.
