I think I am having to cant the rifle because the stock is too thick where I am gripping it. My stock was made for 3P, not pure prone, so it is thicker (taller) near the trigger guard and then gets thinner towards the muzzle, so that the rifle sits higher in the standing position. What I may do instead is try to move my hand further forward to a thinner part of the stock and maybe I'll feel less need to cant. Some people just take a file or rasp to the stock and thin it out where there hand is, but I'm not prepared to do that to this stock. I have been thinking that maybe my prone position is a little high off the ground, so moving that support hand forward is a good experiment for that issue as well.
Whatever the case, once I get settled in I'm pretty confident I can sustain an Expert score with just a little more consistent smallbore practice, instead of going months at a time between matches and never practicing with that rifle. I'm toying with the idea that after I finally shoot an Expert score with the Israeli Mauser I'll focus on making Expert in smallbore, then go back to High Power (with a new bolt match rifle I haven't even shot yet) and finally chase High Master XTC with serious prone skills.
Well, one step at a time, for now my focus is on the Israeli Mauser and proving it can shoot an Expert score in reduced High Power. I have had a minor breakthrough on the SCATT with the Israeli Mauser. I tried a narrower aperture in the rear Mojo sight, such that it creates a thin ring of white around the front sight. This has greatly improved alignment and on the SCATT I am shooting 95+% in slow prone. That is a major missing piece of the puzzle to making Expert with the Israeli Mauser, as all of my sitting and standing positions have both had 90%+ scores in matches, but prone has been dragging down the aggregate instead of lifting it (like it does for most shooters).
And readers, remember, I'm happy to report about your shooting competition escapades as well! Don't be modest and don't be ashamed!