I found that I was able to control how my plastic poured very easily, once I got a digital infra red thermometer like on BaitJunky's site.
Being able to know what the plastic temp is before you pour/shoot lets you vary the temp to get different molds to shoot better.
I do laminates by filling one half of the body in one side of the open mold with one color by hand, and then closing the mold and shooting the second color.
I found I need to shoot at 335-340 to get the second color to go past the first and fill the claws, and to really bond with the first. I could never have done that without the digital thermometer.
Like Apdriver said, just be sure to stir the plastic before you take the temp, because it will be hotter in the middle than on the surface.