corbon ammo can no longer be had, John, even before the virus. The company is dead. As for the 357 sig, and the .400, she has no .40 or .45 assemblies, just 9mm and aint buying any, either. His site doesn't show barrels for the 960 in 1911, just in glocks. Wonder if it's inadvisable? I've shot him an email question about that. I'd never pay the $200 for a barrel. I'd get a spare 9mm barrel from somebody for $60 and deepen the chamber. That's all he's done. Dont even need a lathe to do that. You can hold the barrel in your hand and use a hand held drill for no more material than you're removing. Cooper's Super 9, based upon reamed out 223 brass in a .38 super barrel, got 125 grs to 1750 in a 6", That's considerably outperforming the 960 rowland. Even if you cut the barrel to 5", you're still talking 1650 fps. way beyond what a 357 gets in the same sized gun (ie, 3" barrel, 1400 fps, at best) I have no interest in any of it. The 9x21 was of interest in order to get top speeds in the 3" barrel of the little Sig. I dont want heavier bullets in a 15 oz gun. It's already all she can handle. The blast and flash of the 45 gr, 2200 fps load are horrendous. The spare barrel for the sig was almost $300.