Foxtrot mike?

[Texas Sob]

Opinions on Foxtrot Mike stuff? Complete/stripped uppers and lowers? Want to do a 9mm next are they worth it or better options?

[JB2000]

I just bought a Foxtrot Mike upper and lower and have 100 rounds through them so keep that in mind as you read my comments.

I picked up a 5" rear charging upper that is an exclusive for Rainier Arms and AIM Surplus. It comes with a thread protector and a blast diffuser. I got mine from Rainier Arms and it also came with a set of Kriss Defiance back up sights. The lower (Glock magazine) is their enhanced version with LRBHO, a Defiance pistol grip, nickel teflon GI trigger, QD end plate, ambidextrous selector, and anti-rotating pins. It also has their 9mm weight buffer and a 308 carbine recoil spring. I decided to go with a factory complete upper and lower from a single manufacturer to avoid compatibility problems and the hassle of picking components.

There is no mil-spec or "chart" for 9mm ARs. So how do you determine if one is "quality?" Clint from BRT on here says FM is good to go. The fit and finish on mine looks good. I've noticed different quality of springs and metal parts in different AR kits I've put together. If you put PSA on one end and BCM on the other, Foxtrot Mike feels closer to the BCM end of the scale. The hammer spring is strong and you have to fight it into place. The metal of the receiver end plate is hard and took some effort to stake.

Mine has not been without issues though. I would say the issues are more assembly related rather than the quality of the parts used. First off, when I was attaching the blast diffuser to the barrel, the barrel spun in the upper. The locating pin was either missing or loose and the barrel could be rotated by hand. The upper went back to FM and they fixed it and turned it around quickly. The castle nut was not staked, which is an easy fix. Finally, when I shot it the first time I lost one of the screws out of the anti-rotation pins. It appears no lock-tite was applied.

The magazine well seems a little tight. Magpul magazines go in and out with no issues. However, I have some Glock factory 17 rounders from a Gen 3 that take some effort to get in and out.

The only other thing that gives me a little pause is the magazine release. It's huge and easy to hit but there is no fence around it. If the gun was being used rough I would worry about dropping the magazine. Honestly, I don't know how much of an issue this really is, but most others have a fence.

My first trip out was 100 rounds. It fed and functioned with a variety factory and hand loads from full power to soft and 115 grain to 147 grain. Last round bolt hold open was a must for me and the one on the FM functions great.

Overall I'm still glad I bought the FM. Let me know if you have any questions and I'll do my best to answer them.

Mag well tightness.

[signal4l]

I purchased a complete pistol from primary arms when they first came out. It had a 7 inch barrel, side charging handle, and blast diffuser tucked under the rail. I ran it for over 2000 rounds and sold the upper. I purchased another FM products upper. Couldn't be happier with their products.

The side charging handle on the 7 inch or shorter uppers will prevent you from mounting a front sight, light in the 9, or 3 o'clock position

My new upper has a 7in tri lug barrel and a standard charging handle. Have not shot it yet. I was surprised to find the tri lug was integral. I thought it would have been easier for FM to thread the barrel.

I did try one of their upgraded nickel boron, single stage triggers. It doubled, tripled quite a bit. I switched back to the original fire control group and did not have any problems with that lower.

My lower works fine with Magpul and factory Glock mags. Did not notice any tightness or dimensional problems with magwell.

[arken]

My friends has the FM 9 in both 5" and 7" side charger, also from Primary Arms. They both run great with no issues after close to 2k rounds.

I personally don't like the side charger because my hand actually got burned once from the hot muzzle I can't imagine operating it in a high pressure scenario and low light lol.

I have a Banshee which a little bit nicer and softer shooting especially when I shoot fast. You'd be able to tell the difference.

[Itsahak]

I built two AR 9's last year, both with FM lowers. I used PSA uppers and they mated perfectly. They function perfectly and the only issue I have had is from the Korean made magazines. They required a bit of sanding to fit easily. Glock factory mags and ETS mags fit and feed perfectly. The last round bolt hold open works well and hasn't failed so far. I like them.

[Texas Sob]

Thanks for the replies. I'm still on the fence about building one or just picking up something like a stribog.

[signal4l]

I just shot 300 rounds through my new upper. This is a factory built 7 inch with standard charging handle, factory FM lower. I tried some 27 round Magpul mags and 115 grain Winchester white box. I had numerous failures to feed with these magazines. The 21 round magpuls worked flawlessly

[JB2000]

signal4l,
Interesting about the 27 round Magpuls. I’ve tried 21 rounders and they’ve been fine.

[signal4l]

The springs on a 27 rounders seem much weaker. I believe it's a mag issue.

I did have an annoying problem with my FM pistol recently. The shell deflector is held in place by a screw. I strongly recommend you apply some thread adhesive to yours. The screw backed out on mine and went missing somewhere on the range. I then managed to lose the shell deflector. FM sent the replacement parts to me free of charge.

[JB2000]

Thanks Signal, I’ll pull my shell deflector and locktite the threads. I had the same thing happen with one of my trigger pins. They sent me new ones as well.

Overall the quality seems good, just some assembly issues. I staked my castle but didn’t think to check the screws in the trigger pins or the shell deflector.

Edited to add: I checked my deflector and the bolt is very snug. I don’t think it’s going anywhere but I will continue to check it when I shoot.