700X is mainly a target shotgun powder and burns too fast for steel shot loads. It has some application in cast bullet loads in rifles and handgun loads.
Your main steel shot powders are , Blue Dot, Longshot and Steel.
Lil,gun works well in Lead loads for the 28ga and 410 shotgun plus rifle loads in the 22 Hornet and 218 Bee.
A Lyman Shotgun or Ballistic Products Advantage shotgun manuals are pretty much the bibles on shotshell reloading. If your going to get into shotshell reloading I would suggest having one around as just changing wads can change pressure enough to make your loads overloaded.