+1-800-504-5897 Help Center Check Order Status
About Us Policies Reviews How To
Free Shipping & Free Returns*

FREE SHIPPING on Over 250,000 Products

Enjoy free shipping during the holidays! Shop now and get Free Value Shipping on most orders over $49 to the contiguous 48 states, DC and to all U.S. Military APO/FPO/DPO addresses.

Enjoy Our Extended FREE RETURNS

We want to ensure that making a return is as easy as possible! With our Hassle-Free, Extended Holiday Returns, eligible orders placed from November 12, 2025 on will benefit from an extended return deadline (January 13, 2026 or 30 days after receipt of your order - whichever is later). We'll even cover the cost of return shipping. Learn more about our Return Policy.

  • Entire Store
  • ...
  • Apparel & Footwear
  • Astronomy
  • Everything Else
  • Eyewear
  • Hunting Gear
  • Lab Equipment
  • Military Gear
  • Outdoor Gear
  • Photography Equipment
  • Police, EMS & Fire
  • Shooting
  • Sport Optics
  • Sports & Hobbies
TIP
Shopping Cart

FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5 inch w/ Blast Diffuser Up to $20.00 Off w/ Free Shipping — 2 models

Special offer available for this product. Click here to see!
FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5in Barrel, 5in Handguard w/ Blast Diffuser, Black, FM9U-R55-B
FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5in Barrel, 4in Handguard w/ Blast Diffuser, Black, FM9-RS-54
FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5in Barrel, 5in Handguard w/ Blast Diffuser, Black, FM9U-R55-B
1 of 2 images
FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5in Barrel, 5in Handguard w/ Blast Diffuser, Black, FM9U-R55-B
FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5in Barrel, 4in Handguard w/ Blast Diffuser, Black, FM9-RS-54
2 of 2 images
FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5in Barrel, 4in Handguard w/ Blast Diffuser, Black, FM9-RS-54

Tap Tap to Zoom

Government Export Restriction Government Export Restriction
Government Restriction Government Restriction
Questions & Answers
How do I remove the blast diffuser off the end? I can’t seem to get it off there without the barrel turning. It seems like it has loctite on it. Expert Answer

Email us at Techsales@opticsplanet.com for assistance.

by Ethan, Gear Expert, January 3, 2023
Is this upper compatible with a maxim Defense JP captured spring? Expert Answer

The FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver might work with the JP SCS for Maxim Defense if you are using a Maxim Defense compatible brace. I recommend contacting FM Products to confirm compatibility.

by Hunter, Gear Expert, February 8, 2023
View All Q&A You Have a Question? Ask!
Customer Reviews
Helpful Positive Review
Solid Product - INCORRECT PRODUCT LISTING by Alexander, Verified Owner, April 14, 2022
This upper and bolt are well constructed and I expect it to run as well as any of their Foxtrot Mike products. HOWEVER, the item pictured is a 5" barrel with a 4" handguard. It was only on the invoice (this detail is not on the product page) where it...
Read More...
7/9 found this helpful
Most Recent Reviews
FM-9 5" upper receiver by FM-9, Verified Owner, January 30, 2024
Received this and put first round in and it jammed the bcg.So got it broke loose and round was stuck in bcg would not reject. Had to fire the one round to get it out which was probably not safe. Spoke with customer service with optics planet which I ...
Read More...
Most Recent Reviews
FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5 inch w/ Blast Diffuser by Toby, Verified Owner, January 24, 2024
Worked great, only about 200 rounds so far but flawless. Accurate as can be expected for a short barrel. I put a dot on it. Small and easy to point.
Most Recent Reviews
Foxtrot Mike is a great product! by Brandon Mac, December 9, 2022
I have three in different lengths. Crazy accurate and I have not had one malfunction out of any of them yet. Waiting for tax stamp to suppress a ten and 5 inch barrel. So much fun! Used Sig Romeo 5, foxtrot king slayer, foxtrot sentinel. All 3 zeroed...
Read More...
Read All 4 Reviews
Show In Stock Only
2 Models Available
Handguard Length
All
Search

Product Info for FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5 inch w/ Blast Diffuser

The Foxtrot Mike Products FM-9 Complete 9x19mm Upper Receiver is built from the ground up to provide outstanding reliability and accuracy with a host of top tier features. The monolithic style has been achieved with a proprietary interlock between the upper and handguard. The slim-line handguard is M-LOK compatible for your favorite accessories.image

The Foxtrot Mike Products 9mm Upper Receiver comes fully assembled and ready to drop on any pistol caliber lower receiver that uses Glock magazines. With its full-length Picatinny top rail and M-LOK compatible handguard, the Foxtrot Mike 9mm Upper offers plenty of mounting space for optics and other accessories.

Specifications for FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5 inch w/ Blast Diffuser:

Manufacturer: FM Products
Caliber: 9mm Luger
Barrel Length: 5 in
Threads per Inch: 1/2x36
Muzzle Device: Blast Diffuser
Color: Black
Fabric/Material: Premium Match Grade 41V50
Gun Rail: Picatinny
Gun Make: AR Platform
Gun Model: AR-15
Condition: New
Barrel Material: 4150 Chrome Moly Vanadium
Magazine Included: No
Charging Handle Included: MIL-SPEC
Mount Type: M-LOK

Features of FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5 inch w/ Blast Diffuser

  • Proprietary handguard / upper interlock keeps handguard true to the upper;
  • Complete upper includes bolt carrier group and charging handle;
  • Compatible with 9mm Glock magazines

Package Contents:

  • FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5 inch w/ Blast Diffuser

What firearm models does the manufacturer say FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5 inch w/ Blast Diffuser is compatible with?

The manufacturer says that FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5 inch w/ Blast Diffuser is compatible with AR-15

FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5 inch w/ Blast Diffuser Orderable Models

List of Orderable Models

  • FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5in Barrel, 5in Handguard w/ Blast Diffuser, Black, FM9U-R55-B , MPN: FM9U-R55-B , Code: 3JR-URC-FRC9R5D-FM9U-R55-B
  • FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5in Barrel, 4in Handguard w/ Blast Diffuser, Black, FM9-RS-54 , MPN: FM9-RS-54 , UPC: 3538999 , Code: 3JR-URC-FRC9R5D-FM9-RS-54

FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5 inch w/ Blast Diffuser Unavailable & Discontinued Models

List of Unorderable Models

  • DEMO, FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5in Barrel, 4in Handguard w/ Blast Diffuser, Black, FM9-RS-54 , MPN: FM9-RS-54-DEMO , Code: 3JR-URC-FRC9R5D-FM9-RS-54-DEMO
  • DEMO, FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5in Barrel, 5in Handguard w/ Blast Diffuser, Black, FM9U-R55-B , MPN: FM9U-R55-B-DEMO , Code: 3JR-URC-FRC9R5D-FM9U-R55-B-DEMO
Compare (0)
1 item has been added
Add at least two items to compare