I had decent luck in my Knight with no excuses and BH 209, so unless you were having slight hangfires, I doubt if that was a problem. That said, looks like your bullets are making nice crisp round holes. With my Omega, they would tumble and go through the target sideways. However, they would shoot the maxiballs with a wad pretty well until I got higher than 90 gr of powder. Only real difference there is that the no excuses were bigger (460 gr vs. 370). With the Omega, I was using 777 and pyrodex. I suspect that your QLA is cut better.

There were no hang fires. However, it seems the sound of the rifle firing was kinda subdued on some shots, but that may be my imagination. It doesn't seem the problem is the QLA, because there are 3 maxi holes in the center of the target nearly touching, which i cannot imagine happening if the QLA was the issue. My inclination is the ignition was erratic.

The first shot at 93 yard, missed everything. The second shot which was at 56 yard was high right. The next 4 shots weren't too bad. It could be as the barrel became more and more fouled, the ignition of the powder improved?

Now i am pondering the next step. My thoughts are.. Use a wad. Switch from the rifle primer to magnum shotgun primers. Modify a breech plug so it has a 5/32" flame channel, and a 0.035" flash hole. Start with a fouled barrel. Continue playing with Blackhorn powder. If the adjustments fail to produce consistent shooting, simply switch powder, and see what the results are.

It wouldn't bother me a bit to cut the QLA off, in order to shoot conical out of this rifle, but right now i don't think it will be necessary.