How efficient are magnum charges?

Many of the newer muzzle loaders are capable of handling powder charges up to 150 grains.  The real question is, how effective is this increased charge capability?  The tables below illustrate the velocity produced with various powders, charge volumes, and 2 bullet weights.  Both test bullets are on the light side for muzzleloaders, so results will probably vary with heavier bullets.

All shots used Precision Rifle QT40 Solid 215 (actual weight for solid is 240 gr), cheaper than the Ballistic Tips used later for testing and hunting. The group size listed is theoretical, based solely on velocity variation of +/- one standard deviation.

Powder	Vol gr	Cap	No. Meas	Avg fps	Min fps	Max fps	Diff fps	Std Dev	Grp Size
Pyro P	100	Musket	5	1791	1786	1796	10	4	0.15
Pyro P	110	Musket	5	1835	1830	1838	8	4	0.14
Pyro P	120	Musket	0
Pyro P	130	Musket	0
Pyro RS	100	Musket	5
Pyro RS	110	Musket	5
Pyro RS	120	Musket	5
Pyro RS	130	Musket	5
Pyro RS	140	Musket	5
Pyro RS	150	Musket	5
Pyro Select	100	Musket	5	1688	1660	1709	49	21	0.354
Pyro Select	110	Musket	5
Pyro Select	120	Musket	5	1904	1892	1919	27	16	0.199
Pyro Select	130	Musket	5
Pyro Select	140	Musket	5
Pyro Select	150	Musket	5
Clean Shot	100	Musket	5	1378	1294	1506	212	88	2.19
Clean Shot	110	Musket	5	1403	1311	1446	135	50	1.22
Clean Shot	120	Musket	5	1495	1412	1588	176	63	1.45
Clean Shot	130	Musket	5	1536	1404	1587	183	88	1.82
Clean Shot	140	Musket	0
Clean Shot	150	Musket	0
Pyro Pellet	100	Musket	5	1593	1571	1630	59	27	.51
Pyro Pellet	150	Musket	5	1964	1931	1995	64	23	.29

All tests used PR Extreme Plinkers in 300 gr for comparison. The group size listed is theoretical, based solely on velocity variation of +/- one standard deviation.

Powder	Vol gr	Cap	No. Meas	Avg fps	Min fps	Max fps	Diff fps	Std Dev	Grp Size
Pyro P	100	Musket	5
Pyro P	110	Musket	5
Pyro P	120	Musket	5
Pyro P	130	Musket	5
Pyro RS	100	Musket	5
Pyro RS	110	Musket	5
Pyro RS	120	Musket	5
Pyro RS	130	Musket	5
Pyro RS	140	Musket	5
Pyro RS	150	Musket	5
Clean Shot	100	Musket	5
Clean Shot	110	Musket	5
Clean Shot	120	Musket	5
Clean Shot	130	Musket	5
Clean Shot	140	Musket	5
Clean Shot	150	Musket	5
Pyro Pellet	100	Musket	5
Pyro Pellet	150	Musket	5

From the table we can see some basic trends emerging: