What is an upper and lower

[huntinguy]

I am new to black rifles. I hear a lot of terms like "upper" and "lower". What does this mean?

Rob

 

[fenceline]

Upper and lower receiver halves of specific guns. There are a wide variety of guns that are designed around upper and lower receiver pairings. AR15, Swiss Arms 550, XCR, ACR, SCAR, etc etc.

AR15 Upper...

Fits on an AR15 lower...

 

[huntinguy]

So is the upper where the receiver and chamber are?

 

[fenceline]

So is the upper where the receiver and chamber are?

Two receivers. An upper and a lower. The upper has the chamber as it holds the barrel, which is where the chamber resides.

 

[tootall]

So is the upper where the receiver and chamber are?

The upper is the upper half of the receiver, yes.
Although, for legal purposes, only the lower (in the case of the AR-15) is considered the "firearm". Otherwise, you would have two guns the moment you took one gun apart.