Understanding which pieces make up an AR upper receiver is a good move whether you’re brushing up on your firearm expertise or are new to the realm of AR manufacturing.


The barrel is the most important part of any upper receiver, and it directly affects your precision and performance while using the rifle. Pay particular attention to the spin rate while choosing a barrel to finish your upper receiver. For 5.56 NATO, a 1:8 curve rate is suitable. HANDGUARD

If you’ve ever seen a gun in full-auto mode, you’ll notice that the barrel glows a flaming hot red-orange due firing the heat. If your hand came into contact with the barrel, it would be permanently marked. To prevent such injuries, the handguard protects your hands while also providing customisable rails for sights, slights, lights, lasers, and scopes.

Black 80% Lowers Fire/Safe Engraved (5-Count) | 80 percent lower, Fire  safe, 80 lower jig


The bolt carrier package appears to be a critical component of the upper receiver. Your firearm would not be capable without this component. The gas key, bolt, extractor, and firing pin are all part of the carrier group. When properly installed and maintained, the bolt carrier group ensures both dependability and utility for the vast majority of people.

Final Thoughts:

As a result, at the end of this essay, you should have a better understanding of how tough it is to complete an 80 percent lower pistol that you wish to build. So, what do you have to lose? Follow the steps outlined above to get an 80 percent lower.