NFA C-4 Billet Stripped AR-15 SBR Lower Receiver

Availability: In stock

MSRP: $179.00 Our Price: $169.00 Save 5%

Quick Overview


New Frontier Armory C-4 AR15 Lower Receiver. Machined from aircraft grade Billet Aluminum, not forged and compatible with all standard AR-15 components and magazines.

Machined with enhancements such as: -short throw fire control selector compatibility -captured take down spring (set screw included) -upper receiver tensioning screw -ambi trigger finger rests with grooves -ambidextrous mag release compatibility -threaded bolt catch pin

These are registered with the ATF as 5.56mm caliber w/ 10.5" barrel or 300BLK w/ 9" barrel. Select your choice below.

MSRP: $179.00 Our Price: $169.00 Save 5%
Caliber 5.56mm, 300BLK
Action Semi-Auto; Closed bolt
Barrel No
Length No
Height No
Weight 10.4000
Thread Pitch What thread pitch do I have? Multiple Thread Pitchs Available
Magazine Any Standard MIL-SPEC AR-15
Color Black
Finish Hard Coat Anodized
Materials 7075-T6 aircraft grade billet aluminum
Manufacturer New Frontier Armory (NFA)
Warranty Lifetime warranty against any manufacturer defects when used as directed
Manufacturer's Suggested Retail Price $179.00

NFA C-4 Billet Stripped AR-15 Lower Receiver milled from 7075 T6 aircraft grade aluminum. This lower will accept any upper and/or caliber designed for the AR-15 platform and will accept any standard MIL-SPEC AR-15 magazine. THIS IS A FACTORY REGISTERED SBR LOWER RECEIVER. ALL NFA RULES APPLY.

  • Machined from 7075-T6 aircraft grade billet aluminum
  • Matte black hard-coat anodized per Mil 8625 Type 3 Class 2
  • Precision broached magazine well with beveled feed lips
  • Machined and engraved to be compatible with 45 and 60 degree short throw fire control selectors such as the BAD_ASS ST 45 Lever
  • Caliber marking of "Multi" so it can be used with many different caliber uppers
  • Compatible with all standard AR-15 components and magazines and most aftermarket parts
  • Take down pin spring and detent hole is threaded for a 4-40 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

Ask a Question

  • I understand that I can have any length upper on this lower, but do I have to have an upper the same length as what it is registered with? For example, I have an 11.5" 5.56 pistol upper. Do I need to have a 10.5" upper to go with the 10.5" (5.56), or a

    The ATF asks that if you no longer own or permently change the original configuration (10.5 / 5.56) that you notify them via written letter so the registry can be updated. It is not a requirement that they are notified.

  • The purchase of this item would require a form 4 transfer? Is e-forms still not allowing form 4 transfers and thus paper filing would take 3-5 months?

    Yes, this would require a Form 4 transfer to you, your trust or corporation. As of 6/2/15, electronic Form4 filing is not available to dealers and all forms are filed via the paper method. Form 4s are running 3-4 months.

  • Hello, what is the warranty like on these? I have seen inexpensive new frontier lowers before but never looked twice at em.

    New Frontier Armory offers a lifetime warranty against any manufacturer defects when used as directed

  • Would I still have to get my trust name engraved in the factory registered lower receiver?

    No, this is a factory registered lower receiver and you would not have to engrave your trust information on the receiver.

  • If the receiver is registered with a barrel length of 10.5" can I put an upper shorter than that? Specifically an AR57 6" upper. Thank,Zein

    Yes, you can put any length or caliber upper on a registered SBR lower.