What does "resizing" mean?

[zippygaloo]

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[Telperion]

It means returning the case dimensions to SAAMI specs after the pressure of firing expands and stretches the brass. Take a fired case and try to insert it into your rifle's chamber; it's probably not going to fit. Take a bullet and put into the mouth of a fired case. It will easily fall through into the body.

[markm]

Trimming means returning it's length from "top to bottom".

Resizing means squeezing the case back down to spec, as stated. Think of it as though the case is swollen a bit.

[zippygaloo]

delete

[ar-junkie]

So a case increases in length and expands in diameter when fired?

Thats correct! Also, if you are not saving your brass you should start. Even if you never intend on reloading, someone else may or you could always scrap it for straight cash. Although I'd personally give you more than they would plus shipping. Keep in mind you might want to someday (reload) and what is better than having tons and tons of empties to start with.

I was just thinking if I could have all the brass I have shot all my life that I didn't think was "important"....... I think I'm getting off subject......

[markm]

So a case increases in length and expands in diameter when fired?

A necked down case will stretch a little when fired. But the bigger portion of stretching happens when the expander ball on a resizing die is pulled out on the up stroke.