80% C-45 Billet Lower Receiver — Glock Style Mags
Manufacturer: New Frontier Armory
Model: 80% C-45 Billet Lower Receiver
Type: AR-45 80% Lower Receiver — milled from 7075 T6 aircraft grade aluminum billets
Caliber: Multi (will accept .45/10mm, and other Glock large frame caliber magazines)
Magazine: Accepts any Glock style large frame pistol caliber magazines in .45ACP/10mm, and other calibers
Weight: 16 oz before finishing
Other Specifications and Features of the 80% C-45 Billet Lower Receiver:
- Machined from 7075-T6 aircraft grade billet aluminum
- Tumbled in ceramic media — Ready for blasting and your choice of firearm coating once you complete the machining
- Precision machined magazine well with beveled feed lip for easy mag swaps
- Compatible with most standard AR-15 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 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-45 rifle from the ground up exactly the way you want it configured and shoot for less!
**NOTE – Please read the FAQ below regarding adjustment of your ejector before use and ensure you re-assemble with Loctite or similar threadlocker to prevent screws from backing out over time.
Completion Jigs & Fixtures can be found in the “Tool” category or by CLICKING HERE
California Bullet Buttons are available by CLICKING HERE
Pistol Caliber Specific LPK is available by CLICKING HERE
QUESTION: Do I need to adjust my ejector?
ANSWER: Yes, before firing your new pistol caliber lower we suggest you adjust your ejector. Loosen the two screws holding the ejector in to where it becomes a semi-tight friction fit. Ensure the ejector is seated all the way to the rear and all the way down in the pocket. Close your upper onto the lower with the bolt all the way forward. SLOWLY cycle the bolt in and out about 1/4 of the way back a few times then let the bolt close all the way and tighten the ejector screws. They are cupped to get a good grab on the SS ejector, so only hand tight or you risk the chance of bending the ejector over. Any slight rubbing at this point will wear in the ejector after a few magazines are cycled through the gun. If you see excessive rubbing you can also file down the top corner on the left side of the ejector (shooters left). At this point you should remove one screw at a time without disturbing the ejector location and add locktite to the screws and tighten them back down. This will ensure the screws will not back out over time.
QUESTION: What jigs can I use to complete this 80% lower?
ANSWER: Because of our mag well design, any jig that attaches to the REAR of the mag well will work for completing this lower. Other jigs can be modified to fit around our mag well and will also work. We sell a jig that works with all other 80% lowers on the market including our G-15, C-4, C-10, C-9 and C-45 lowers which you can purchase by clicking HERE.
QUESTION: What type of magazines will fit in this lower?
ANSWER: The lower was designed to fit and drop free factory Glock large frame pistol magazines. Although it accepts and shoots other aftermarket magazines 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 Glock factory specifications.
QUESTION: Do you offer a reliable last round / empty magazine bolt hold open (LRBHO) System for this lower?
ANSWER: YES — After watching several companies try and fail to incorporate a RELIABLE last round bolt hold open (LRBHO) system into their lower receivers we decided to take a different approach and will be incorporating our LRBHO technology (PATENT PENDING) in our matching upper receivers. After rigorous testing and hundreds of hours of research and development, we feel that this is the best option for LRBHO on a Glock magazine AR style firearm. Our upper will be compatible with other manufacturers lower receivers that either don’t have a LRBHO or you can scrap the non-working LRBHO out of your existing AR-45 Glock Mag lower and solve the issue of not having a 100% functioning LRBHO. For more information on our matching Pistol Caliber Upper, please CLICK HERE.
QUESTION: What bolt carrier group will work with a Glock magazine fed AR-45?
ANSWER: You will need an AR-45 Bolt Carrier Group that has relief cuts to clear the Glock style magazines. Our Standard .45 BCG can be found here.
QUESTION: What LPK will work with this lower?
ANSWER: Although we sell a specific LPK with just the parts needed to build the C-45 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-45?
ANSWER: It is advised that you use a 10 oz or heavier buffer. Lighter buffers aren’t safe to use in a blowback system with larger calibers such as the .45ACP and 10mm, and they may not feed some types of ammunition reliably without the added weight.
The New Frontier Armory 80% C-45 Billet Lower Receiver is proudly MADE IN THE USA by hard-working American men and women.
THIS IS NOT A FIREARM — NO FFL REQUIRED — CAN SHIP DIRECTLY TO YOUR HOME!!
All GCA and NFA rules apply when you complete this project. Please ensure you fully understand your local and federal laws before completing this 80% blank into a functioning receiver. New Frontier Armory will not be held responsible once this blank is altered in any way.