What is this casing?

[dbaz]

My wife found this on the trail during our hike. It's 0.45"OD and the neck is approximately 0.24"OD x 0.18"ID x 0.62"L.
It's been smashed, obviously, but it looks like it is necked-down twice.

Anyone know what it is?

[GunNut666]

It looks like a 308 blank. Google 308 blank and look at images. I'm pretty sure that's what it is.

[dbaz]

That was quick...you nailed it. A blank never occurred to me. Thanks!

[Dodahdude]

Well I drew a blank on that one!

[Sutcliffe]

Be here all week, will we?

Well I drew a blank on that one!

Yeah, the case mouth is usually a tip off.