An odd Western XPERT shotshell Now with pics

I have edited this from the original post to replace the sketch with pictures and make the text match them.

I picked up this shell (on right) at SLICS, in a bulk buy. It’s shown next to an AA with standard height low base for comparison.
The cup is only 3/16 high and is strongly reactive to a magnet but appears to be washed with aluminum. The hull is the one piece compression-formed plastic, typical of other shells I have dated to the late 1960’s. I know Olin experimented with aluminum a lot, I have some paper hulls with aluminum cups, but this is a washed steel and I’ve never seen any from this period (aluminum washed). I’m thinking this is an experimental or limited run. Comments welcome.

Could you see it this is magnetic just above the head? Might indicate a magnetic inner-reinforcement?

I’ve not heard of aluminum-washed steel heads. Not that that means anything.

I believe I have some of these that are 20 ga. and some 12bore. I will dig them out. I seem to remember that they were steel/magnetic as some have a little rust growing. I kept quite a few as they reload the same as AA. I sold them in my store. They were priced as as promo. I might even have and old box…If it survived my cleanup this spring.

Pete, I thought of that and ran the magnet over in several patterns to check and as far as I can tell, the cup is steel and nothing else. I’ve never seen any compression formed Olin hulls with a liner but…

It’ll be interesting to see what you have Sportclay. I would not expect this hull to be loaded as a promo because it was their 1st line as far as quality went (XPERT MARK5)

Sorry for the delay. I am in the process of packing for moving. I rummaged throught my bins of empty hulls looking for these empty hulls and found a 20 ga hull that is headstamped WINCHESTER 20 GA steel head but not as short as the one you have. It has no markings on the outside of the case body shallow striations and an 8point crimp. There is at least 10,000 20ga hulls to go through and I know there were some of the very low brass steel head cases as I thought they were unusual. If I had the boxes they are gone now. I will keep looking. The very low brass head AA were fairly common (12 bore) and I remember the unusual short steel head. I don’t throw away reloadable hulls so unless they were worn out I have them somewhere.