While they all pretty much function the same, there are some differences that may or may not be worth the additional money depending on what you feel is important to you. Let’s dive into some of the things that set billet and forged upper and lower receivers apart.
Is Billet Better?
There are tons of debate between billet and forged so I won’t go into that. However, I find billet receivers to be much better finished. I don’t think that has much to do with the fact that they are billet but I do think manufacturers just put much more care into finishing billet receivers. The billet finishes tend to be much smoother, somewhat shinier and just look better aesthetically. Even among billet receivers, there are differences. Noveske has some of the cleanest finishing, even better than POF, which comes in 2nd in my opinion. Seekins Precision billet finish is nicer than their forged counterparts.
Lower Receiver Options
Most of the billet lowers come with integral winter trigger guards. I believe the consensus here is that it’s a must have upgrade. You can add a billet guard to forged lower receivers for around $18 or a Magpul MOE polymer enhanced guard for around $9. More importantly, some billet lowers come with an ambidextrous bolt release. This is what the Magpul BAD lever is designed to do aftermarket. Having a built-in ambi release is a big plus for some people especially left handed people or people who train for transition shooting. Some billet receivers have flared mag wells so that you can change mags easier. Lancer actually goes 1 step further and allows for users to change the mag well to 3 different sizes. Aero Precision and POF have recessed screws instead of roll pin for the bolt release. This might seem trivial, but it makes it easier to install and prevent damaging your receiver during assembly. This roll pin is the most difficult to install and is the easiest to damage your receiver though there are ways to avoid doing that. Most billet receivers are also enforced in various places where the manufacturers consider to be “weak” on standard receivers. Whether or not you buy into that is up to you. I haven’t heard of any report of broken AR15 receivers due to these “weak” points.
Upper & Lower Fitment
The key difference is actually in the fit of these different receivers. They are all “mil-spec”, but that is really the minimum and as some would argue a starting point. Some are much tighter than others but you are essentially at the mercy of upper and lower pairing. It usually works best to pair uppers and lowers from the same manufacturer. Some (Aero, BA) follow the path of POF-USA and add a plastic tension screw to allows for upper and lower to fit tight in case the upper is too loose. The Accu-wedge solution will cost a few bucks, but serves the same purpose. I personally don’t like having things other than designed parts placed inside my firearms.
What Should I Choose?
That’s really going to come down to what the purpose of your firearm will be used for. If you want to build a RECCE rifle then you’ll want something that will be lighter so every ounce you can cut will benefit you. If you’re looking for a safe queen that only comes out once every few months to hit the range then you’ll probably want the fit and finish that comes with billet. One of the greatest aspects of the AR-15 platform is just how modular it is so there is usually something for everyone.