Forged Vs. Billet Lower Receivers

Aaron Spuler is a firearms enthusiast and recreational shooter. Follow more or his work at The Weapon Blog

Regardless of whether you’re building your own or purchasing one off the rack, owners of an AR15 have one thing in common, and that’s dependable and durable operation for many years to come.

When making a choice, you’ll hear terms such as billet or forged lower receivers and it can be a little confusing as to which one is the best. To make an informed decision, it will help to understand the differences between billet and forged.  

Billet

Billet production means producing the part from a single piece of metal. Using a CNC or Computer, Numerical Control machine, a manufacturer can create stringent and precise manufacturing standards.

When machining a lower receiver, think of billet production as ensuring the metal grains are all running in the same direction. What you get with a billet machined part is a pretty substantial piece of equipment that’s cut or machined from a single piece of metal.

While it has been proven that a receiver machined from billet is not as strong as a forged receiver, it allows for many more unique customization options at the factory.

Forged

While you may decide to do a ton of internet research before choosing, what you may discover is that not everyone believes billet machining will provide the endurance and performance you need.  

Most experts will agree that forged receivers, whether upper or lower are the best and strongest. Think of the forged production process this way. The method of forging metal together, regardless of whether it’s cold hammer forging or not, forces the grains of metal to follow the contours of a receiver which results in greater strength.

 Forging means forced compliance to form with and ultimately results in a much higher degree of dependability and endurance. Many AR-15 enthusiasts look for another even more critical aspect of forged versus billet production.

Billet produced AR15 receivers might not fit when combined with a mil-spec forged receiver due to different dimensions however, the most important dimensions like trigger pin holes, takedown pin holes are Mil-Spec. The thinking is that if the upper or lower receivers are good enough to pass rigid military specifications, a commercial version that’s Mil-Spec is undoubtedly the one to get.

Forging is also a process of heating the metal then pressing it into a mold. This process compresses the grains of the metal together more firmly and thus creates a much stronger piece.

Unless you’re building an AR-15 with a unique and shape or functionality, most forged parts will be the only way to achieve a Mil-Spec build.

The net result of a forged steel part is that it’s ultimately a much stronger product than a machined billet-produced part. But not to worry. If Mil-Spec isn’t something you care about or don’t need, a billet-produced product is plenty strong enough to handle recreational shooting at the range or those many hunting trips on your schedule.

Building or Buying on a Budget

Most often, the difference between an upper or lower receiver that’s manufactured by billet machining, or a forged process is how much you’re willing to spend.

Traditionally, upper, and lower receivers that are CNC machined cost more than forged ones do. It’s all about the individual process of making the part and has nothing to do with the resulting quality.  

Remember, the billet process starts with a single metal block, and the CNC machine then shaves it into the desired shape. The metal block must always be more significant than the resulting part, which means a lot of metal shavings end up on the cutting room floor.

Unfortunately, the problem is not just about the wasted metal. Any billet-produced part requires expensive cutting machines and takes much longer to produce as the metal block must be turned several times during the process. The blades used during billet production are costly, and often, the manufacturer must halt the process to allow them to cool.

With the forging process, the initial spend for the equipment necessary is approximately the same as billet production, but it’s the process that lowers the cost. Think of billet production as a unique cutting of the metal each time. With forged production, while the initial equipment expense is similar, the production process is much higher, and the cost to produce each piece is much lower.

A good rule of thumb here is how much you’re willing to spend.

Custom Versus Common

Depending on how you intend to use your AR15, picking billet-machine AR15 parts and forged parts may be a non-starter. Since billet machined parts allow a sleeker-looking rifle with more straight lines and ninety-degree angles, the thought is if you want that custom over a more traditional look, purchasing billet machined parts is often the way to go.

However, as you see, the trade-off is a more expensive rifle and less durability. While the choice is, of course, always yours to make, the three things you’ll want to settle on are how much you can or want to spend, how you want your rifle to look, and how you plan to use it.

Each manufacturing process has a unique fit in the marketplace. Whether you’re looking for that one specific modification that will make your AR15 look amazing or hoping to get the best bang for the buck, both billet machining and forged production can provide you with some of the best solutions.