This came up last week in the Builders Forum...As I stated then, the flintlock that I built in 1988 has a small Siler on it...It is a .54 caliber and a inch and a sixteenth barrel at the breech...The gun functions just fine and I have used it for deer and competition shooting since I made it...
If my memory serves me correctly, the gentleman that halped me get my parts together back then recommended the small Siler over the large because of speed and the smaller hammer is lighter so the rifle shouldn't move as much during the fall of the hammer, helping in accuracy...
Now, dangifino if this is true...I also have a large Siler on another rifle and both work just fine...
We must remember that there were many restocks and guns made from parts from other guns back in the day...If a gunsmith had a smaller lock and a customer waiting then why wouldn't he use what he had???