Thanks all.
I was surprised at how tricky it was to get the pose realistic looking. I formed the armature in the spread eagle position and then bent him into shape. The torso wire broke because of all the repositioning. I left it separate as I figure I will need to sculpt the clothes on the legs and torso separately until I get to the coat, or at least the tails of the coat. This is all a learning process. Previously I have only modeled standing figures from scratch using air drying clay or sculpy.
You are right that having formal positional shooting training helps get the pose correct. Using the skeleton to support the rifle is critical to being a good marksman. I posed the figure assuming that a good marksman would use a good position regardless of the period, assuming that he would have learned by formal training or through experience.
I have noticed that some figures posed with various weapons are unrealistic or un-natural because the center of gravity of the weapon isn't taken into account. This is tough to understand with firearms as a lot of sculptors have not been able to handle one.
Nearly all firearms of the 1690 to 1870 period had a center of balance just forward of the front of the lock plate. In other words, if the hand is placed with the little finger lined up with the front of the lock plate, the gun will be balanced in the hand. This is true even with the heaviest of muskets. This is NOT true of American long rifles, which tended to have heavier barrels and the ballance was further forward.
Matchlocks and guns earlier than the 1690's tended to be more front heavy. The earliest ones required forks to hold the barrel steady.
I have seen 1700-1860 figures posed with a gun balanced on the shoulder with an arm placed on top of the butt of the gun attempting to look like the arm is counterbalancing the gun. In reality, the arm would tip the gun off the shoulder. A more realistic pose would be to have the center of balance behind the shoulder and have the hand pulling down on the barrel. This is an example. The pose ruins an otherwise nice figure.
https://www.tlbminiatures.com/store/p225/TLB_050_75mm_First_Rifle_Regiment_1812.html
Well, thanks for the kind comments and I apologize for the rambling post.
Mike