View Full Version : Guide to Billet Lowers

24 December 2008, 09:33
Billet AR15 Lower Receivers

A common question that we are asked, and that we often see on boards is what is the difference between the various billet lowers, and are they worth it. Here is an overview of most of the billet lowers we are familiar with.

Whether they are worth more than their forged brethren is debatable, but there isn't much question that they have a unique look, and tend to cost more to produce than a forged lower. The end answer for me is whether a lower is in spec or not. When I say spec, I don't mean mil-spec, because unless its got a hole drilled for the auto sear, its not mil-spec. I mean the holes need to be in the proper places and sizes. The threads need to be clean, and the magwell needs to be correct. Aside from these things, the lower is simply a shell with a logo. If you want your shell to look nicer, or have a certainly name on the side, that is up to you.

Where billet lowers get a chance to be different is with a more flared magwell, ambi bolt releases, integrated trigger guard, and a few other cosmetic differences.

Manufacturers Websites




http://www.noveskerifleworks.com/ (included as they are the only ones to sell the Magpul Billet Lowers)


24 December 2008, 09:33
POF-USA Patriot Ordnance Factory

Here are the POF lowers shown on a few different setups. POF was one of the earlier modern billet lower manufacturers. They made changes that were more than simply cosmetic, and the ambi-bolt release may be one of the more notable features found on any billet lower.

All POF lower receivers are machined from 7075 aluminum, and are type III hard coat anodized.

POF has three different generations of Billet lower receivers.

* CNC Machined from Solid Billet
* Stronger than Castings
* Reinforced for Receiver Extension Tube
* 7075-T6 Aluminum
* Milspec Hard Anodized & Dark Black Finish
* Marked Multi Caliber for your Building Needs
* Flared out Magwell for Speed Loads


* Integrated Trigger Guard
* CNC Machined from Solid Billet
* Stronger than Castings
* Reinforced for Receiver Extension Tube
* 7075-T6 Aluminum
* Milspec Hard Anodized & Dark Black Finish
* Marked Multi Caliber for your Building Needs
* Flared out Magwell for Speed Loads


* Integrated Trigger Guard
* CNC Machined from Solid Billet
* Stronger than Castings
* Reinforced for Receiver Extension Tube
* 7075-T6 Aluminum
* Milspec Hard Anodized & Dark Black Finish
* Marked Multi Caliber for your Building Needs
* Flared out Magwell for Speed Loads
* Ambi-Bolt Release










24 December 2008, 09:52
Sun Devil MFG

Sun Devil MFG has been producing a 6 series aluminum billet receiver for several years, and last year included an upgrade in the way of a built in, adjustable tension screw. The screw is located under the pistol grip, and permits the user to adjust the lower to the upper receiver it is to be mated with. No longer do builders have to be concerned with whether their lower will fit sloppy with an upper. The screw is coated, and will not mar the finish of the upper it interfaces with.

Sun Devil has several different colors and coatings available, and it should be noted that the lower pictured in the below images in one of mine which is an early model. The grayish color is now black, and matches nicely with most upper receivers.









24 December 2008, 10:29
Tactical Innovations Inc.

Tactical Innovations Inc. is recent into the billet receiver scene, and gives the following checklist as a reason why they believe their orderings are superior to the others on the market. While their checklist is marketing oriented, it is still a quick and easy way to grab an overview of what they feel is important. All items in the list can be found on other billets lowers, but there is no point in coming to the market with a low speed version of a lower when others have already raised the bar. The features offered are ones that I think most people will appreciate.

1. Precision Machined
2. 7075 Allow (Not 6061)
3. EDM Machined Magwell
4. Laser Engraved
5. No Pistol / Rifle Designation
6. Multi Caliber Marked
7. Upper Receiver Tensioning Screw
8. Rear Detent Capture Screw
9. Hand Finished

While machine marks are a little more evident on the lower that I have than some others, I don't think it detracts from the look at all.






27 December 2008, 13:35
Magpul lowers (MPLA) have been the most sought after lower that I can remember. These lowers are the product of a no holds barred, "make the best AR15 lower" brainstorm. Magpul as a company was built up as a weapon accessory manufacturer, and while they were able to alter their license and become a weapon manufacturer for the purposes of this Magpul MPLA project, their insurance company was less than willing to cover them as a "weapon manufacturer". The MPLA project was put on the back burner for awhile as Magpul continued work on the Masada (later becoming the ACR), as well as other component and weapon projects.

John Noveske, of Noveske Rifleworks, is well known through the weapon community as a man of character, and with a company that refuses to compromise in its quest for a superior weapon system. In late 2008, Noveske Rifleworks and Magpul were able to sit down and figure out a way to use the Magpul lowers in a Noveske build. With insurance companies happy, or at least out of the way, the project was given the greenlight, and on 12/17/08, the first ever Noveske/ Magpul project was launched. This went forward not as a single rifle purchase, but as a larger package, which included the following:

16.1" Cold Hammer Forged Barrel, 1 in 7" twist, 5.56mm
--Made of Mil Spec M249 Machine Gun barrel steel, with heavy M249 Chrome Lining,
(appx. 2 times as thick as an M4 or M16)
--Extended Feed Ramps
--Mil Spec Phosphate finish
--MP HP tested
--Mid-Length gas system, no M203 notch
--Shot peened and MP tested bolt
--Properly staked carrier key
--Auto carrier
--H Buffer
--MAGPUL UBR buttstock
--Ambi magazine catch
--Ambi bolt release
--Forged Vltor MUR upper receiver featuring an anti-rotation interface with the handguard
--11" free floated handguard w/ 1913 rails
--Low-profile gas block pinned to barrel
--Flip-up front and rear sights
--AAC Blackout non-mount flash suppressor
--Four MAGPUL P-MAG 30rd mags included, black non-window
--V-TAC padded black sling
--QD Sling Swivels
--MAGPUL XTM rail panels, 5 packages
--Eagle LE Discreet Soft Case

MPLA lowers can be broken down into three different types.

Series A lowers are the ones which have the ambi bolt release. The include the integral trigger guard, and flared magazine well, as well as the rest of the features of the B series lower.

Series B lowers look the same on the left side (non-ejection port side of the weapon) as the A series, and feature the large Magpul logo just like the A series. The sole exception to the list of features is that the B series does not have the ambi-bolt release. This may or may not be a big deal to some people, but as hard as it is going to be to find a Magpul MPLA lower (or weapon), its almost a moot point.

Series C lowers are sometimes referred to as the "china doll" or "asian girl" lowers. These are similar to the B series lowers, but can not be sold. They are easy to spot as the little figure (e-port side of the weapon) appears to be flipping off the viewer (or other agency).

This first image is of a stripped MPLA lower. From this side, there is no way to tell if it is an A or B series.


Shown below is a Series A lower, note the ambi mag release.



Shown below is a C series lower.