Re: 223 handloads
Use a lot of powder and fast burning. Not really.
Actually I'll be you get more replies if you give some pertinent data. Rifle type, barrel, chamber, what you are going to use it for, distance, what you 'll shoot IE paper, yotes etc....
Simply looking for speed won't accomplish much and may not be what you are after. Especially at longer ranges.
Get as close as you can, but utilize your skills as needed.