Winchester Western 20ga 2 3/4in hulls

[Fox]

I have a bunch of Universal and Western hulls, from what I can find the Universal you can use the AA data but do not expect them to last very long but I am curious about the Western hulls.

Lyman for their slugs shows Compression formed and HS hulls as identical, these Western hulls look to be built like the HS hulls.

The data shows pressures at 10,300 - 10,900 psi, so still low compared to SAAMI specs of 12,000psi, would I be getting into any danger running Win HS/AA data for these other Win hulls that look to be built exactly the same as the HS?

Thanks

 

[Lefty Dick]

Use the data for poly formed hulls!

 

[Fox]

Use the data for poly formed hulls!

Comparing the data the polyformed hulls take more powder to get to the same pressure as the AA/HS hulls with the same other components, thinner wall potentially?

 

[Fox]

Use the data for poly formed hulls!

The Lyman manual shows that the Polyformed hulls can use AA and HS data, but they do not even list a polyformed 20ga hull.