Well I FINALLY got myself to the range and Chronographed all my worked up loads. Due to time and economy reasons, I only shot 2 or 3 of each load but this data puts me in the ballpark anyway. All of these were shot out of my .50Cal, Knight USAK American Knight with a 22, 1:28 twisted barrel, using CCI #11Mag caps and Triple Seven powders. So, for your viewing pleasure, here are my results:
Bullet; Charge; Muzz. Vel; Muzz. Energy
1) 300gr XTP Mags; 80gr 2fg 777; 1501fps; 1501 ft lbs.
2) 300gr SSTs; 80gr 2fg 777; 1490fps; 1479 ft lbs.
3) 300gr Precision QTs; 80gr 2fg 777; 1477fps; 1454 ft lbs.
4) 300gr Precision DCs; 80gr 2fg 777; 1400fps; 1306 ft lbs.
5) 300gr Barnes MZs; 80gr 2fg 777; 1452fps; 1405 ft lbs.
6) .490 Round Ball; 70gr 2fg 777; 1544fps; 953 ft lbs.
7) 348gr Aero Powerbelt; 90gr 2fg 777; 1403fps; 1521 ft lbs.
8 ) 348gr Lead Powerbelt; 90gr 2fg 777; 1425fps; 1570 ft lbs.
9) 350gr PrecisionExtreme; 90gr 3fg 777; 1485fps; 1714 ft lbs.
10) 350gr Precision QTs; 90gr 3fg 777; 1563fps; 1899 ft lbs.
11) 360gr Prec. Plinker; 90gr 3fg 777; 1509fps; 1821 ft lbs.
12) 385gr GreatPlainConical; 85gr 2fg 777; 1343fps; 1542 ft lbs.
13) 460gr NoExcuses Con.; 90gr 2fg 777; 1259fps; 1619 ft lbs.
14) 385gr NoExcuses; 85gr 2fg 777; 1384fps; 1638 ft lbs.
(.45cal in sabot)
15) 400gr Precision QTs; 100gr 3fg 777; 1519fps; 2050 ft lbs.
16) 400gr PrecisionExtreme; 100gr 3fg 777;1474fps; 1930 ft lbs.
All this data pretty much confirms what I had thought all along. This rifle has a sweet spot where it prefers its loads around a certain velocity. In this case, it likes its sabots running around 1500fps, conicals around 1325fps, and its PowerBelts around 1400fps. I can only ASSUME that other muzzleloading rifles will react this way too having a preferred velocity sweet spot. Hopefully some of you here can apply this data for your own work ups in the future. Also as a reference, I should note that these 1500fps loads are listed as 1600fps loads on Hodgdons Load Data for 777 I reckon that difference is probably caused by my shorter 22 barrel.
And the good news out of all of this is that all of these loads are very accurate. I was NOT concentrating on accuracy for these tests so I shot all 40 shots (16 different loads) into the same target at 25 yds. At the end of the day, every single shot had passed thru a 2 hole left on the center of the target. So the point of impact at most muzzleloading distances are functionally identical for all of those loads. SWEET!!!