Foxtrot Mike 9mm Upper from Primary Arms

[akjunkie]

Picked up a Foxtrot Mike 9mm Upper from Primary Arms.

This guy here:

http://www.primaryarms.com/fm-products-16in-9mm-complete-upper-with-brake-fm16-9mm-3-mb

It arrived today. It was my impression the "Rear Trapdoor" was suppose to keep the BCG from falling out. Based on some youtube vids it look like the Rear Trapdoor has a tang missing. Possibly broke off.

And the chamber and rifling is pretty filthy. I know MFGs usually test fire their uppers with couple rounds. Looks like my barrel seen couple hundred.

I've already emailed PA.

Looking for feedback from Calguns. Anyone else here have a FM Upper?

Is my Trapdoor broken? Or normal?

Pics included in attachments.

This video here @ 1:22 & 1:25 looks like there is a tang on the bottom of the Trapdoor?

https://www.youtube.com/watch?v=lU5BZpsB2Bs&t=103s

[caliguy93]

is the trapdoor retained by the lower receiver at all? I was looking at that exact upper since the forward charging feature is awesome.. dirty chamber is no big deal and iv received many uppers that were dirty or dusty. though they didn't have any fouling from being fired.

[akjunkie]

"is the trapdoor retained by the lower receiver at all?"

I dont believe so.

[caliguy93]

looking at this video it seems like there is nothing that keep that trapdoor from swinging open and shut

https://www.youtube.com/watch?v=9X7XUFRVEeg

6:30-6:40

[caliguy93]

this video also describes the exact question you have in the first 2 minutes

https://www.youtube.com/watch?v=D_Ep1zSF0cI

[akjunkie]

Been doing some research. Looking at the pics at Primary Arms. The BCG does stick out with the Trapdoor closed. However if you pull the BCG out far enough the Trapdoor will hit the "gas key".

PA description states the front Charging Handle is ambidextrous. I dont think this is true with the 16in barrel. At FM website they show the 9mm PCC Colt upper has a hex screw located in front of the handguard near muzzle that allows you to remove the Fold down charging handle and swap to other side. With the 16in barrel the CH is located near the "middle" of the handguard. I dont see a hex screw for removal of CH.

I gave my barrel is real good scrubbing. Rifling looks good. The Lands are shiny. Grooves still got some powder residue.

Guess I'll keep it and see how it shoots.

[Strykeback]

Been curious about that upper as well. Specifically the shorter ones to swap out on one of my pistols. Would that trap door have any issues with a break action fixed mag california option or does it stay closed after mating the upper and lower every time?

Sent from my SM-G930V using Tapatalk

[akjunkie]

Been curious about that upper as well. Specifically the shorter ones to swap out on one of my pistols. Would that trap door have any issues with a break action fixed mag california option or does it stay closed after mating the upper and lower every time?

Sent from my SM-G930V using Tapatalk

The Trapdoor can open while mated to lower receiver.

[akjunkie]

Have my FM upper mated to a New Frontier Armory 9mm lower. Hard time removing front pivot and rear take down pins. They are in tight. Need to tap out with screwdriver.
FM upper mates fine with my other lowers. Anderson, Riflegear, CMMG, etc.

Damn, did I get a lemon? More I play with this FM upper they more I hate it.

[Strykeback]

Have my FM upper mated to a New Frontier Armory 9mm lower. Hard time removing front pivot and rear take down pins. They are in tight. Need to tap out with screwdriver.
FM upper mates fine with my other lowers. Anderson, Riflegear, CMMG, etc.

Damn, did I get a lemon? More I play with this FM upper they more I hate it.

New frontier lowers like many of the higher end lowers has a tension screw near the back bottom to tighten the fit between the upper and lower. Did you try adjusting that at all? Your description wouldnt bode well for my setup with juggernaut tactical pins.

Sent from my SM-G930V using Tapatalk

[78marz]

I just got one too. Still looking for a designated 9mm lower. FM states that the upper won't work with every lower.

[tay]

I have one on a Spike Tactical 9mm Lower.

As mentioned 'Trap door retained by lower receiver'.

Overall a great upper for 9mm Glock AR build.

[tay]

The trap door on my upper.


Sent from my iPhone using Tapatalk

[akjunkie]

The trap door on my upper.


Sent from my iPhone using Tapatalk

Tay,

Thanks for posting a pic of your Trap Door. The triangular hole on my Trap Door looks squished / deformed.

Primary Arms forwarded my email to FM Products.
A day after I cleaned my barrel and lubed my Upper / BCG I get an email from FM asking me to send my upper back.

Shipping my Upper back to them tomorrow. I'll keep everyone posted.

[sigstroker]

I just got one too. Still looking for a designated 9mm lower. FM states that the upper won't work with every lower.

There's a youtube showing the FM upper on 3 different lowers. PSA is one of them.