I had no lube issue with Pyrodex. I assume Real BP will be similar for you.

I tried moderate powder loads equivalent to 80 - 90 grains volume of Pyrodex RS-2f in 2.5 grain increments.

For Pyrodex P-3f, this is about 74 - 86 grains volume. With BH 209, it's about 59 - 72 grains volume. I found best accuracy at 85 grains of P and 71 grains of BH 209. These are both velocity equivalent to about 89 grains of Pyrodex RS-2f, estimated at about 1300 fps.

Accuracy and consistency improved with the wad, but at slightly higher, ~ +2.5 grains, powder charges. The lubed wad has some mass. Maybe the increased powder is to make up for that mass and get back up to the sweet spot velocity for the gun.

I found a reference that says an MMP ballistic bridge sub-base weighs 13 grains. When I was using it with a 385 grain bullet, I had to add 3 grains of Pyrodex P to get back to accuracy sweet spots. Math confirms this is what is needed to maintain same velocity for 398 grains of projectile vs. 385.

I was using an Eastern Maine Shooting Supplies lubed felt wad. I don't know it's weight, but the gun seemed to say it needed 2.5 grains of P to make up for it.

I found accuracy to be very sensitive to small changes, apparently even changes in daily weather. Sweet spot accuracy isn't great, about 4", sometimes with flyers. Clean cold barrel flyers have been as much as 18" off group POA.

My conclusion at this point is that it's due to the QLA, because sabot loads are far more forgiving. For instance, with the .45/300 XTP and the black 45/50 TC sabot, many loads from 80 to about 110 grains Pyrodex RS equivalent shoots less than 4" groups. The sweet spots are 1.5" groups and don't seem to be affected by small changes or weather, other than rain.

Best accuracy load I've found is .44/270 Speer DCHP, Harvester .44/50 crush rib sabot, and 82.5 BH 209. This one is more sensitive to changes, but has made some centerfire guys leave the range vowing to trade for a muzzle loader.

Good luck and share how the QLA works with No Excuses.

Bill