In firearms terminology and at law, the firearm frame or receiver is the part of a firearm which integrates other components by providing housing for internal action components such as the hammer, bolt or breechblock, firing pin and extractor, and has threaded interfaces for externally attaching ("receiving") components such as the barrel, stock, trigger mechanism and iron/optical sights.
A disassembled Mauser action showing a partially disassembled receiver and bolt
AR-15 rifles showing their configurations with different upper receivers. The lower receiver is visible at the bottom
Glossary of firearms terms
The following are terms related to firearms and ammunition topics.
The Steyr AUG, the first successful bullpup rifle
A clip being inserted into a Karabiner 98k
A view of the break-action of a side-by-side double-barreled shotgun.
A field stripped Thompson submachine gun