WOW! I'll bet it kicked, and it is a wonder it stayed in one piece. The standard charge for the .69 caliber musket was 70 grains!
That was the charge for the .69 minie ball.
The 1837 specs were as follows;
Musket cartridge; Ball dia. .64". weight 397.5 grns. Powder charge 144 grns. including 8-10 grns. for priming. "Buck & Ball" cartridge was the 144 grn charge with the addition of 3 .31" buckshot on top of the round ball.*
The 1841 manual listed the ball dia. as .64". weight = 18 per pound. Charge 130 grns. Musket powder. The musketoon load was the same ball on 85 grns. Musket powder. Buck and Ball load used the 130 grn. charge with 1 ball & 3 buckshot.*
The 1849 specs were as follows;
Musket cartridge; Ball dia. .65" 17 balls per pound. Powder charge 110 grns. Musket powder. The musketoon load was the same ball on 75 grns. Musket powder. Buck and Ball load used the 110 grn. charge also adding 3 buckshot.*
The 1855 specs for the "altered" musket list a ball dia. of .685" and a weight of 730 grns. on a charge of 70 grns. Musket powder. This is the Minie ball cartridge for the 1842 Rifle Musket.*
*Source: "Small Arms Ammunition in United States Service. 1776- 1865 by Berkley R. Lewis. Smithsonian Institution Press 1956. Smithsonian Publication Number 4254
I have a .69 cal. musket and shoot it with a charge of 110 grns Fg black powder. The Fg seems to better represent the Musket powder than does FFg. Experimentation with substituting Fg in place of FFg in loads for both .69 and .58 cal. Muskets and Rifle Muskets resulted in bullets hitting the same point of aim with noticably less felt recoil. Weapons used by myself and my brother were; Original 1777 French .69 cal musket (perc. conv.) , Original Harper's Ferry 1842 Perc. Musket, Euroarms repro 1853 Enfield "3 band" Rifle Musket, Parker Hale repro 1858 "2 band" Rifle and Antonio Zoli "Zouave" Rifle. We used the same bullets/balls and the same volume measures of powder.