20x110mm Oerlikon by West Band Aluminum Co., Wisconsin

This fired 20x110mm Oerlikon from Wilmot-Breeden, Birmingham measures 109mm in length. Was that the brass expansion sideways which took away 1 mm? I have no live Oerlikons and no way to compare.

The neck of the Oerlikon case was not supported by the chamber on firing, and so was blown out into an entirely different shape, reducing its length.

You can compare your fired case with the 20x110RB in this pic:

  • @ sksvlad: I’m very sorry to inform you but the 20X110RB brass shell case from your photo is NOT British made, it was manufactured in Wisconsin by “West Band Aluminum Co.” which between 1941-45 made “Mk2” and “Mk4” 20X110RB Oerlikon brass shell cases. => The same company from Wisconsin but using the maker’s mark “WBA” also made 20X110 Hispano rimless brass shell cases in 1952-53. I hope this helps, Liviu 01/24/09

Thanks, Liviu, I’ll change the header of this post. Now, if you may be so kind as to look at my Hispano post (a different post).

The actual name of the maker is West Bend Aluminum Co., of West Bend, Wis. The second war contract for 20m/m cartridge cases is mentioned in the firm’s online history. JG

  • @ J. Gill: Yes, you’re 100% right, it is my mistake. Liviu 01/26/09