Technically, the above use of the term "square load" is incorrect. As long as we all understand what JBL means by it, when he's referring to equal volumes of shot and powder, we're safe and sound. But, used properly, the term square load references the amount of shot that is necessary in any bore size to provide a shot column height equal to the bore's inside diameter. i.e., a .729" bore would require a shot column of .729" height to be considered a square load. The use of the same volume of propellant behind it doesn't make it a square load, as I have always understood the term.
I agree that equal volumes of FFg and shot (EVSP) will likely work well for you in that 14. For more detailed information on m/l loads get ahold of V M Starr's writings on it. But, EVSP has always worked well enough for me that I have never found the need to load otherwise, for birds or clays. But, if you're really into tuning patterns with a m/l shotgun that is unchoked (CYL) remember this old axiom:
Less powder, more lead, shoots far, kills dead. Lowering the ratio of black to shot will usually slightly tighten the patterns, at a given range. Consequently, increasing the amount of black, in relation to the amount of shot, will usually open patterns.
Here's a great read for "new to m/l shotguns enthusiasts":
http://traditionalmuzzleloader.com/index.php/loading-the-smoothbore-gun Best wishes ........
