Field stripping a firearm means to take it down without the use of tools.

Field stripping most often involves separating the slide and frame (or separating the receivers, if the receiver is held together by pins, like some rifles), and then breaking down the constituent parts without the use of tools. This generally includes the barrel assembly (in pistols), the bolt carrier group, and the recoil spring (action spring).

This often precludes taking the smaller assemblies apart (bolt, extractor, ejector, striker assemblies, etc.) especially in semi-automatic pistols.