pistol powder

If a small gun shop we’re to start stocking reloading supplies, what powders and primers are going to be the most popular for rifle, pistols, and shotguns? Also, what brands of brass and or bullets?

Hello guys & gals. So... disclaimer - I know juuuuuuust about nothing about reloading so far =D; so don't be too critical lol. But I see a big drawback to short-barreled .223/5.56 AR pistols being the noise & fireball that comes out of the barrel. Could you remedy this by reloading .223 with...