I loaded my Ruger for years from the flask, and no mishaps. However, I've lately started using one of Track of the Wolf's non-adjustable powder measures (stock M-030). Powder goes from flask to powder measure to the chamber without any spillage. Of course, the revolver is in a stand on the bench, otherwise it would be impossible to juggle revolver, flask and measure. Several years ago I shot a relay loading from a flask with a crudded up spout that I determined later was throwing anywhere from 10 to 22 grains of 3F. I think using a measure makes it easier to see that you're completely dumping a full measure and hence the same charge each time.