I think chances are good that if you are shooting the blue sabot with copper jacketed bullet now that you can shoot just about any copper jacketed, copper or cast, .40 cal bullet in the same sabot. If you stumble across a bullet that loads a bit stiff in the plain blue sabot, try it in a crush rib. Also, if your gun is tight enough to launch a sabot other than those ELR things, your gun is likely tight enough to do a full-length trial slug test with your rod to see if the barrel has any loose spots which might get in the way of your being able to shoot a .45 cal bullet sabotless. Use a 3/8" wood dowel about two inches longer than the entire barrel length and gently tap a .50 cal round ball into the muzzle end then use the dowel to tap the ball thru the barrel, slowly actually it should just push thru with not a lot of pressure. If you notice an area that needs greater pressure or simply lets the ball and rod slip thru without any real pressure, then you may have a problem and may not find shooting sabotless doable reliably. Honestly I think by loading a sabot you should be able to tell if there are spots in the barrel that are too tight or loose, but with the lead ball trick you can measure across the grooves in the ball and help determine what diameter bullet you need to shoot sabotless.
I'm ordering those Fury .40 cal star tips for one of my .45 rifles so I can expand a little from the XTPs I currently shoot in one and will be shooting in the other to move to the star tips when the gun is sighted.
Granted, the .40 cal fodder used in sabots with a .45 may almost look like a stigma but really that's not the case. The worst place to shop for .45 bullets in in the box stores. Going on-line is you friend here. And, as others have alluded to, casting your own lead bullets can bring you a bit closer to your gun and its capabilities.
Congrats on your acquisition and enjoy your shooting!
