Photo graphics for concepts and terminology.

JimDandy

New member
Does anyone have any graphics for things like shoulder bumping/neck sizing, headspace, case "anatomy" (i.e. this is the belt, the shoulder, the neck) and so forth? I know I don't always do well translating the written word into an imagined visual picture. I was thinking if we can get this stuff all in a sticky so when people ask about headspace, loading to the rifling, neck vs full length sizing etc there's a graphic to point to.
 

dmazur

New member
The Sierra reloading manual has a fairly good technical explanation of headspace, with lots of pictures of incipient case head separation, blown heads, etc. But no labeled drawing such as you suggest.

See post #24 in this thread for a good graphic -

http://thefiringline.com/forums/showthread.php?t=524003&highlight=cartridge

I'm not suggesting this is what you want, nor can I offer its use. I'm just linking to it as an example of a good graphic.

And, while the SAAMI drawings are wonderfully complete, there is so much information presented that a newcomer is probably quickly lost.

A few months ago, I was involved in a thread on this forum which attempted to delineate and define the various uses of the term "headspace". It was amazing how the term is misused. There is a correct definition, and yet there is a common use which is incorrect. And confusing.

The task of simplifying this to a few images sounds daunting.

How can it solve the problem of someone who has read that he has to have no more than 0.002" of headspace for optimum brass life, and then he sees the graphic labeled 1.634" - Headspace?
 
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mehavey

New member
The task of simplifying this to a few images sounds daunting.

How can it solve the problem of someone who has read that he has to have no more than 0.002"
of headspace for optimum brass life, and then he sees the graphic labeled 1.634" - Headspace?
Subtraction. :D :p :D :D
 

Bart B.

New member
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_and_information/index.cfm

For a glossary of terms and conventions:

http://www.saami.org/specifications_and_information/index.cfm?page=glossary

The term "headspace" probably has the most definitions across the shooting sports than any other word. SAAMI's glossary says it's:
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
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.
 
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