I think the best "glossary" and "drawings" for cartridge and case (as well as barrel and chamber) parts and dimensions are in the reference documents from the Sporting Arms and Manufacturers Institute (SAAMI). These two are pretty good:
For information and specifications:
http://www.saami.org/specifications_...tion/index.cfm
For a glossary of terms and conventions:
http://www.saami.org/specifications_...?page=glossary
The term "headspace" probably has the most definitions across the shooting sports than any other word. SAAMI's glossary says it's:
Quote:
The distance from the face of the closed breech of a firearm to the surface in the chamber on which the cartridge case seats.
|
One often heard definition for "headspace" I've heard is
Quote:
The distance between the head of a fully seated cartridge or shell and the face of the breech bolt when the action is in the closed position.
|
According to this glossary's definition of "head clearance," which states this one's commonly confused with headspace, is not a surprise to me.