C-5 Billet Lower

$169.99

  • Manufacturer: New Frontier Armory
  • Model: Stripped C-5 Billet Lower (MP5 Mag) – Anodized – Packaged w/ Hardware
  • Caliber: 9mm
  • THIS ITEM MUST SHIP TO AN FFL
  • Bulk Qty Discounts Available at 25+, 100+ and 500+ Units
  • Discount will appear in your cart when logged in
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In stock

SKU: C5LOWER Category:

Description

 Stripped C-5 Billet Lower (MP5 Mag) – Anodized – Packaged w/ Hardware

Manufacturer: New Frontier Armory

Model: C-5

Type: Stripped Lower Receiver — milled from 7075 T6 aircraft grade aluminum billets

Caliber: 9MM

Magazine: MP5

Weight: 0.75 pounds

C-5 Lower Billet
C-5 Lower Billet

 Other Specifications and Features of the Stripped C-5 Billet Lower (MP5 Mag):

  • Machined from 7075-T6 aircraft grade billet aluminum
  • Matte black hard-coat anodized per Mil 8625 Type 3 Class 2
  • Precision machined magazine well with beveled feed lip for easy mag swaps
  • Machined and engraved to be compatible with 45 and 60-degree short throw fire control selectors such as the BAD_ASS ST 45 Lever
  • Compatible with most standard AR-9 components  and most aftermarket parts
  • Take down pin spring and detent hole is threaded for a 6-32 set screw for easy capturing (hardware included)
  • Upper tension screw behind grip screw (threaded hole with hardware included) to adjust any “slop” out of vertical fit between upper and lower
  • Ambidextrous trigger finger rests with grooves (above and below mag release/mag catch)
  • Threaded bolt catch pin (Threaded hole and hardware)
  • Integrated large opening “winter” trigger guard
  • Proprietary magazine catch assembly, feed ramp, and ejector is included and installed at the factory
  • Manufactured to MILSPEC (where applicable) on state of the art CNC equipment for consistent quality parts and exacting tolerances
  • Save money by building your own AR-9 rifle from the ground up exactly the way you want it configured and shoot for less!
  • **NOTE — You must use an upper that has widening cuts to accept the larger width MP5 Magazines — We sell three versions of C-5 Uppers that can be found HERE.

Pistol caliber specific LPK is available by CLICKING HERE

Magazines can be found HERE
**NOTE:  ETS magazines may require slight sanding to ensure proper fitment due to variations from factory H&K Magazines.  We have yet to find any fitment issues with HK, Zenith, or KCI mags.

FAQ:

QUESTION: What type of magazines will fit in this lower?

ANSWER: The lower was designed to fit and drop free factory MP5 9mm magazines.  It has also been thoroughly tested with many aftermarket magazines to fit and drop free.  Although it accepts and shoots other aftermarket magazines (KCI, etc) some slight modification may be needed to get them to drop free from this lower because of the varying width measurement we have seen when checking these magazines to H&K MP5 factory specifications.

 

QUESTION: Do you offer a reliable last round / empty magazine bolt hold open (LRBHO) System for this lower?

ANSWER: NO, like the original MP5 platform, there is no LRBHO function.  You must use either our C-5 Slick Side Upper or our C-5 Non Reciprocating Side Charging upper as they are widened to accept the MP5 magazines.  Other manufacturers make uppers cut for MP5 mags as well, but we can’t guarantee their compatibility at this time.

 

QUESTION: What bolt carrier group will work with a MP5 magazine fed AR-9?

ANSWER: Both AR-9 BCG’s that we sell (CLICK HERE for AR-9 BCG’s) will work in both MP5 Mage AR-9’s as well as traditional Colt style AR-9’s and Glock Mag AR-9’s.

 

 

QUESTION: What LPK will work with this lower?

ANSWER: Although we sell a specific LPK with just the parts needed to build the C-5 lower receiver HERE, any standard AR-15 LPK will work.  You will not need the magazine catch assembly, bolt catch roll pin, or trigger guard that are normally included with standard LPKs.

 

QUESTION: Do I need to use a special buffer when I build my AR-9?

ANSWER: Although its not technically required, it is advised that you either use a 9mm buffer (longer and heavier than carbine) or a spacer in your buffer tube before you place your spring in.  The reason for this is to limit the BCG travel to the rear so it doesn’t come back forward and smash the bolt catch hard enough to break it.  The 9mm BCG is shorter than a standard BCG.  You can use a carbine buffer with a spacer (WHICH YOU CAN PURCHASE BY CLICKING HERE).

 

The New Frontier Armory C-5 Stripped Billet AR-9 lower receiver is proudly MADE IN THE USA by hard-working American men and women.

 

FIREARM WARNING:

This is a serialized item considered to be a firearm by BATFE.  This item must be shipped to a Federal Firearm License (FFL) holder.  All BATFE, GCA & NFA rules apply!  This item must be shipped to a Federal Firearm License (FFL) holder.  You will be prompted at checkout to pick an FFL to ship to in your area using our FFL Locate tool. YOU will be responsible for checking with your local FFL to ensure this weapon is legal in the state that you reside and that they will accept this weapon on your behalf and transfer it to you. New Frontier Armory, LLC will NOT be responsible for any shipping or admin charges incurred by packages not being accepted by the FFL you choose during checkout.

Additional information

Weight0.95 lbs
Dimensions9.5 × 4.5 × 2.25 in

Questions and answers of the customers

  1. 0 votes
    Answered by the admin

    No, there is not an upper receiver on the market compatible with an MP5 mag lower that provides a LRBHO function.

  2. 0 votes
    Q What Ambi mag release works with these? answer now
    Asked by Nic on May 31, 2019 7:52 am
    A

    We're not aware of any that are compatible.

  3. 0 votes
    Q Can this lower accept mp5 40 magazines? answer now
    Asked by Jeremy on May 28, 2019 9:16 am
    A

    Yes.

  4. 0 votes
    A

    That's not an option that we offer at this time as these lowers require an MP5 magazine, which are illegal for most consumers in the state of California.  We have not tested any magazine lock features on this model.

  5. 0 votes
    A

    Line up hole in ejector with screw, tighten.  Locktite can be used on the screw to help hold it in place.

  6. 0 votes
    Q Does the ejector require adjusting? answer now
    Asked by loboslanding on April 14, 2019 1:43 pm
    A

    When you're ready to complete your build, line up hole in ejector with screw, tighten.  Locktite can be used on the screw to help hold it in place.

  7. 0 votes
    A

    A representative spoke with Fostech at the 2019 SHOT Show and was informed these triggers will work; however, we haven't tested either brand to date.

  8. 0 votes
    A

    Absolutely, we recommend KCI and sell them as well.

  9. 0 votes
    A

    Yes, it needs to be 100% tight to prevent feeding issues. Apply medium strength thread locker to prevent future loosening.

  10. 0 votes
    Q What is the fastener size for the upper tension screw? answer now
    Asked by terry.stansberry on March 17, 2019 8:33 am
    A

    1/4-28"

  11. 0 votes
    A

    We haven't tried that one specifically, but there should not be any fitment issues.  Battle Arms Development has a similar brace that fits on our C5 lowers with no issues.

  12. 0 votes
    Q What hardware does it come with? answer now
    Asked by Rick on February 9, 2019 1:27 am
    A
    • Take down pin spring and detent hole is threaded for a 6-32 set screw for easy capturing (hardware included)
    • Upper tension screw behind grip screw (threaded hole with hardware included) to adjust any “slop” out of vertical fit between upper and lower
    • Threaded bolt catch pin (Threaded hole and hardware)
    • Proprietary magazine catch assembly, feed ramp, and ejector is included and installed at the factory
  13. 0 votes
    Answered by the admin

    Yes, as long as your dealer will accept this lower we can ship it to any state.  You and your FFL are responsible for knowing your state laws.   Because of dealer and distributor contracts we have in place, we are not allowed to offer any type of discounts at this time, sorry.

  14. 0 votes
    Answered by the admin

    They would work on our C-9 possibly, but not on the C-5.  The C-5 requires a wider dimension inside the upper to accept the larger MP-5 style magazines.

  15. 0 votes
    Q Would I need your BCG to run the MP5 mags? Or can I use a standard AR9 BCG? answer now
    Asked by fabian.mcglasson on January 6, 2019 12:58 am
    Answered by the admin

    Most standard AR-9 BCG's made in the last few years should work just fine.

  16. 0 votes
    Q Will a f1 upper UDR-15 3G be compatible with the c-5 lower answer now
    Asked by Matt on December 29, 2018 9:18 am
    Answered by the admin

    No, more than likely it would need modification to widen it for magazine clearance.

Send me a notification for each new answer.

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FIREARM WARNING

This is a serialized item considered to be a firearm by BATFE. This item must be shipped to a Federal Firearm License (FFL) holder. All BATFE, GCA & NFA rules apply! This item must be shipped to a Federal Firearm License (FFL) holder. You will be prompted during checkout to pick an FFL to ship to in your area using our FFL Locate tool. YOU will be responsible for checking with your local FFL to ensure this weapon is legal in the state that you reside and that they will accept this weapon on your behalf and transfer it to you. New Frontier Armory, LLC will NOT be responsible for any shipping or admin charges incurred by packages not being accepted by the FFL you choose during checkout.

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