Thanks Doc,
A half in powder slide is fine for .357, but it's probably not the best choice if you want to get up to 22 grains of 2400. The biggest Hornady Pistol Powder bushing will only get you to 15.5 grains of 2400, but if you remove the bushing and just use the 1/2" hole you can throw a charge of around 21.5 grains of 2400.
For 22 grains of 2400, you would be better off with a 5/8 powder bar.