Well, it happened. Threw my balls into the air, they came back down I know where.
Interesting trial it was. I fiddled with minor stuff along the way but will let you know what/where/ etc and all y'all can do with it as you please. Short version? I found my load on the first go-round.
Couple of points for your consideration. Super low load density can manifest as wild velocity variations. But you already knew that probably. What surprised me somewhat was the numbers were surprisingly consistent depending on the orientation of the charge. Let it rest in the forward part of the case and velocity was low, muzzle up before you shoot and it is MUCH higher. You will see on the picture below some outlandish variations, but they were so because I was changing the game routinely with each load. I also relate that with exception of the Red Dot the powder fouling was remarkably heavy. No surprise there. There was no leading whatsoever.
First round was the center X and is the same load fired over the chrony in the earlier post. 1.5 gr Bullseye. All shots had powder settled to the rear of the case except the last and it accounted for the large velocity spread.. Next up was the upper left, followed by upper right and lower right. Number 2 load was 1.8 gr Bullseye and the 4th shot had the powder forward and again, accounts for the velocity dip. It will be my squill load nonetheless.
Red Dot flyers were generated by powder forward and the 700X group has the top 2 holes from powder forward. Fact of it is, the POI was reasonably predictable based on my antics. That they shot this well was a bit of a surprise. 20 yards by the way and round balls work thru a suppressor with very little noise.
Dry patched the barrel after the two Bullseye loads, in order L-R and the last patch was the result of 10 shots. As suggested above, Red Dot did not powder foul at all.
So.....OK....I'm bored again. Got my new BB gun and it's hog rated. First blush of cool weather I'm headed to the swamps to bust its cherry.