Sean, thanks for stopping to say hello at my Bridger seminar up at Fort Bridger Sunday. Sorry I didn't recognize you, I confused you with someone I met two weeks ago after a few years and he looked like you. I did not have the trouble with the English Sporting rifle that you show. Just looked at my chronograph book, and most groups looked good. For other readers, this rifle has a 32" Rice round bottom groove Jaeger barrel with a Chambers English Fowler flintlock. The barrel is as good as there is. I shot nine targets from rest at 50 yards and the best round groups came with 80 grains of Goex 2F or Olde Eynsford 2F and 1 1/2F. Loads of 50 grains of Goex 3F or Olde Eynsford 3F the rifle did not group as well. I probably gave you my test targets, but for others, here is charge and velocity: All balls are Hornady .530, all charges are from weight-calibrated individual measures except the first two from an antler, about 52 grains.
52 grains Goex 3F, .021/.009(crushed reading) tan linen patching, 8 shots gave 1253 fps. Patches holed. Round group, OK.
52 grains Olde Eynsford 3F, .022/.014 linen, patches holed, 7 shots 1341 fps. Group larger. I had a cleaning patch on the seating jag and wiped the bore between groups.
80 gr Goex 2F (all measures calibrated to individual charges and powders) .021/.014 soft canvas used from here on. Patch on jag also. 6 shots 1506 fps. Tight round group.
80 gr OldeE 2F, ditto above, 5 shots 1534 fps,good group.
80 gr OldeE 1 1/2F ditto above, 6 shots 1510 fps, good group after first shot fouled the cleaned bore.
50 gr Goex 3F, ditto above, 6 shots 1222, open group.
50 gr OldeE 3F, ditto above, 5 shots 1225 fps, group strung vertically.
80 gr OldeE 3F ditto above, 5 shots 1556 fps, big group.
100 gr OldeE 1 1/2F, ditto above, 5 shots 1703 fps, had to reuse one patch (ran out), good group.
My issue with this rifle was that I could not shoot it well off-hand, and that is what I needed it for. So I built a 32" 1 1/8 x 1" GRRW barreled flintlock with a 12 1/4" LOP weighing 9 3/4 pounds, basically a copy of my Jim Bridger rifle which I shoot very well off-hand. The Sporting rifle weighs about 7 1/2 pounds.
If I did not give you my test targets, let me know and I'll find them and send them to you.