Issues With the Ohio Tool Plow Plane

I've had this Ohio Tool #96 plow plane for a number of years now and I really love using it. So much so that I haven't used my Lee Valley plow plane since I fixed up the wooden plow. But recently I worked on a project that required cutting a groove in the ENDS of a board, and the Ohio Tool plow was not up to the task. It cuts great (usually) when going with the grain, but across end grain was not good.Ohio Tool Co. #96Left side viewMy set of Ibbotson ironsFrom right, numbered #1 (1/8"), #2 (3/16"), etc. through #8 (5/8")Probably 99% of the grooves I make are 1/8", 3/16" and 1/4". The iron that inspired this post is the 3/16". I'm trying to figure out why it's not performing as well as I would like.To get a comparison, I pulled out (for the first time in several years) the Lee Valley plow plane to test it making an end grain groove. It performed very nicely, with the groove having a smooth bottom and walls.Nice clean groove in end grain - Lee Valley plow with 1/4" ironSo this had me…