I received a box of new HSM .303 Savage today and it arrived with Bertram headstamps. Before seeing these, the only modern .303 Savage headstamp that anyone would ever find much would be the PPU brass, or the Jamison stuff. Quality Cartridge also does a little bit of it, and Roberson lists it on their website as one which they can produce, but their website only shows a drawing.
The PPU brass has been the mainstay for the past few years for brands like Precision Cartridge, who also uses PPU brass in 7.7x58. I find this interesting in that these are two calibers which PPU does not do loaded ammo for in the U.S. market, but only the empty brass for smaller manufacturers. I say “smaller”, but Hornady even uses PPU brass for the Graf & Sons contract load in .303 Savage, which is the only instance I am aware of in which Hornady uses another brand’s brass with that brand’s headstamp instead of their own.