Last year I worked up some loads in a old-school Douglas barrelled Pennsylvania .45 rifle. I was looking to hot-rod a Douglas barrel flintlock, and started with a Douglas barrel percussion Pennsylvania. This is .45 cal 1:66 twist, deep groove rifling. I tried drilling a hollow base in .45acp soft boolits and they would group, but felt loose in the bore as if they would fall out pointed muzzle down.
Then I tried a thin muslin greased patch with regular pistol flat base, they gripped the barrel well, and, grouped. I tried 230gr TC, .45cal HP, and Lee 200RNFP, with my little muslin patch and they all grouped well. I tried a .40cal Hornady XTP in a sabot it grouped good too.
......But I didnt have a chronograph at that time.....
Now I got one.........
Here goes:
All data is soft cast except for the Hornady .40cal in a sabot, and all is black powder.
Pistol bullets are loaded with a thin muslin greased patch cut in narrow strips to form a X patch on loading, as cast flat base,
1. 40cal Hornady XTP loaded in a plastic sabot, 70gr 3f GEOX, 1st shot is a leftover from last years deer season, shot out of a cold bore 1810fps
followed by, 1707fps, 1578, 1685, 1713
2. .452 HP 230gr soft lead, 60gr 3f, with the X patch, 1494fps, 1445, 1518
3. .45 Lee 200gr RNFP, 60gr 3f, X patch, 1518fps, 1530
ran out of 3f powder.
Got some 2f Geox powder and continued.
4. .45 Lee 200gr RNFP, 60gr 2f, 1357fps, 1391
5. .451 round ball with pillow ticking spit patch, 70gr 2f, 1820fps, 1697, 1691
6. .45 Lee 230gr TC, 60gr 2f, 1396fps, 1356, 1356
7. .40cal XTP in sabot, 80gr 2f, 1759fps, 1755, 1787
8. .451 RB, spit patch, 80gr 2f, 1852fps, 1854
got tired, went home.
note: none of these today were shot for groups, as groups were experimented with last year to determine viability of shooting pistol boolits out of a slow twist round ball barrel.
All of these will stabilize out of a 1:66 barrel, but NONE were shot for a tight group today.
This is chrono speed data only, and data that they do indeed stabilize in 1:66"