The correct way to solder would be to "tin" the wire first. Then insert it into the pin. Heat the pin by putting the tip of the iron on the barrel of the pin and then flow solder into it. For a good connection you want even heat. Filling the pin with solder then shoving the wire in is not going to give you the best result. It may work but you could have a cold solder joint.

With that said, you are going to need one hell of a iron to get that hot enough. That may be intended for a crimp.