Case head/ web stretch

[fuzz]

Hia folks
Regarding only case head web stretch, when do you all consider too much stretch and chuck the brass?
My criteria for years has been, when using An RCBS case master, for instance on a 0.473" rim bottle neck, if the thickness drops to more than half before and after the trough and it is less than 15 thou thick at that point – I chuck it.
I'm curious to see where on the analytical Richter scale I am at!

Thanks in advance

Dwayne

 

[Potashminer]

Not certain I completely follow you, but if I detect any thinning of the case wall in front of the web, on the inside, I consider that my fire forming and/or re-sizing sequence has failed me, so I no longer use that brass. Else, primer pockets getting loose fit for primers, or necks splitting. Pretty much only reasons that I "chuck" brass. I try to load and sort in lots of 50 brass or 100 - when a few display symptoms I do not like, the entire batch gets "chucked" and start with fresh stuff. I am not a competitive target shooter, nor do I spend any time on a "formal" shooting range. Am lucky enough to load my shooting table and seat into back of 1/2 ton truck, and set up to shoot within 10 minutes of my home. Don't really want to leave my stuff out there - lost a set once, do not want to lose another...

 

[fuzz]

Thanks potashminer. Looks like the simplicity of the OP from July 15 "case seperation", is better stating what I was trying to ask.
Dwayne

 

[bigedp51]

Below these .308 cases were fired in a new Savage bolt action rifle and full length resized every time.

The chart at the bottom shows at what firing and how much the cases stretched and thinned. You can see some cases failed after .008 and one failed after stretching and thinning .019.

The quality of the case, its thickness, brass hardness, amount of shoulder bump, and chamber pressure effects case life.

Below is a .303 British cartridge being fired in an Enfield rifle. The amount of head clearance , headspace and quality of the case affects how much the case can stretch and thin.

An example, I have had brand new Winchester .303 cases stretch and thin .009 on their first firing. And in the same rifle a Prvi Partizan cases did not stretch at all on their first firing. So to answer your question, when do your cases start to stretch and thin. And how much do they thin after each firing and how much head clearance/shoulder bump do the cases have.

Another example, my 30-30 cases at 38,000 cup or 42,000 psi never stretch and thin. This is because the chamber pressure is not great enough to push the case back into the bolt face.

Below I bought my RCBS case mastering gauge after I started collecting Enfield rifles. I wanted to know if it was my reloading methods or head clearance that was effecting case life. The answer was both, with the amount of head clearance and brass quality having the biggest effect. And regardless of brass quality, minimum shoulder bump has the biggest effect on case life.