Ask just about anyone about the Browning High-Power and they will say it's a great pistol, 9mm luger fan or not. I've seen High-Power conversions done in .40 SW, but I've never seen one in 357 Sig, which is a great pistol cartridge. Why not is what I want to know? Is it even possible? Could a High-Power withstand the pressure that the 357 Sig generates? I would think dropping a 357 Sig chambered barrel into a .40 SW converted gun would bring about the desired effect, and I would also think it would feed well, seeing as the 357 Sig is a bottlenecked cartridge. It sounds like a good combination to me. Any thoughts?

~thebuckheadkid

You could buy a new .40 Hi Power and convert it with a .357 SIG barrel. EFK Fire dragon makes the barrels, for one. I don't think converting a 9mm HP to 40 would be a good idea to start with, FN changed the design significantly from 9 to 40.
Andy
https://www.efkfiredragon.com/products.php?cat=46