Jeff Siewert

And then the next item is tapered, gradually tapered material properties that ensures each portion of the case can do its job correctly.

You have stronger

But lower elongation and failure at the aft end, basically the extractor groove area, and then softer but more ductile near the case mouth.

So when you go to resize them, kind of where all the work's done is up near the shoulder and the case neck.

And so that's where you really got to apply the lubricant when you go to resize.

Okay.

Headspace control is dictated by gun needs, sealing, feeding, that sort of thing.

So that's kind of on the gun designer.

And then lastly, the design margins.

are determined by the percent of ultimate strain, not by stress.

So almost all of these cartridge cases, if you're operating in pressures above kind of even modest pistols, so if you're operating above, say, 20,000 PSI,

the case is going to stretch some and it's not going to come back to its original dimension.

So that case has, engineers would call it yielded.

So you've pushed the stresses above the yield point.

And so as a result, you know, most engineering things

you look at what's the factor of safety.

Well, cartridge cases, factor of safety is not a valid design criteria.

It's really percent of ultimate strain.

And ultimate strain is really just, okay, if you stretch this material until it fails, what percent of that does each of the sections of the cartridge case see?

Okay.