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Q&A for FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5 inch w/ Blast Diffuser — 23 Questions & 16 Answers

Name FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5 inch w/ Blast Diffuser (4.3)
$349.00 $329.00 Save $20.00
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Q
Smith, member, from AL, United States, asked on December 21, 2022

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
A
Answered by Ethan, Gear Expert, from IL, United States, on January 03, 2023

Email us at Techsales@opticsplanet.com for assistance.

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Q
Scott, member, from WA, United States, asked on December 18, 2022

Is this upper compatible with a maxim Defense JP captured spring?

Expert Answer
A
Answered by Hunter, Gear Expert, from OH, United States, on February 08, 2023

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.

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Q
Jack, guest, from NV, United States, asked on December 03, 2022

Is this a full auto rated upper?

Expert Answer
A
Answered by Ethan, Gear Expert, from IL, United States, on December 07, 2022

Yes, the FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver is rated for full-auto.

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Q
Smith, member, from AL, United States, asked on September 15, 2022

Will this fit on an AR9 lower

Expert Answer
A
Answered by Ethan, Gear Expert, from IL, United States, on September 26, 2022

Yes, the FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver is compatible with any pistol caliber lower receiver that uses Glock magazines.

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Q
Zac, member, from VA, United States, asked on July 27, 2022

The pictures and descriptions do not match. I want to ensure I purchase the correct handguard length. It appears you have them reversed.

Expert Answer
A
Answered by Ethan, Gear Expert, from IL, United States, on August 08, 2022

The FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver (MPN:FM9-RS-54) features a 5" barrel with a 4" handguard. While (MPN:FM9U-R55-B) features a 5" barrel with a 5" handguard.

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Q
Joe, member, from CA, United States, asked on June 24, 2022

Is the bolt carrier ramped to work with AR-15 drop in trigger?

Expert Answer
A
Answered by Hunter, Gear Expert, from OH, United States, on September 23, 2022

FM Products does not state if the BCG in the FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, is ramped or not. However, the information I could find does state it will work with AR triggers. So I recommend contacting FM Products to confirm compatibility of the FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, with your particular trigger.

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Q
Ted, member, from NY, United States, asked on June 08, 2022

Do I need to file the NFA tax stamp forms to build with this as a rifle? Would it make it an SBR?

Expert Answer
A
Answered by Hunter, Gear Expert, from OH, United States, on October 14, 2022

The correct ATF forms and tax stamps would need to be filed and approved to build the FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5 inch w/ Blast Diffuser into a rifle.

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Q
Ted, member, from NY, United States, asked on June 02, 2022

Wouldn’t this make my rifle an SBR? Do I need to do the paperwork for NFA tax stamp and everything?

Expert Answer
A
Answered by Hunter, Gear Expert, from OH, United States, on June 16, 2022

That would depend on the lower receiver you are placing the FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver, 5 inch on and the rest of your set up. Please email us at techsales@opticsplanet.com for more information.

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Q
Northpole, member, from FL, United States, asked on May 24, 2022

Is this all I need to convert my AR15 5.56 Pistol to a 9mm?

Expert Answer
A
Answered by Hunter, Gear Expert, from OH, United States, on June 01, 2022

In order to use the FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver on an Mil-Spec AR15 lower you will also need a mag well adapter that is compatible with this upper. The manufacturer recommends using the Sylvan magwell adapters with their uppers. The manufacturer also recommends using a heavy buffer and buffer spring.

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Q
Northpole, member, from FL, United States, asked on May 19, 2022

Is this all I need to convert my Ruger AR pistol to 9mm?

Expert Answer
A
Answered by Hunter, Gear Expert, from OH, United States, on June 06, 2022

Yes, the FM Products FM-9 AR 9x19mm Parabellum Rear Charging Upper Receiver can be used with the Ruger AR Pistol lower. You may need a different trigger that can be used with 9mm. You will also need a magwell adapter. Please email us at techsales@opticsplanet.com so we can help you find what you need.

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