The short guns without forend would indeed be held under the cylinder and close to the trigger guard. Filling the chamber mouths with lube, was not practiced 'back then', but wads were used, according to Elmer Keith - as he was taught.

Longer mil-spec rifles with fore end wood and 28" or longer "musket barrels" were too heavy for a rear hold - thus the gauntlets.

Ring firing was rare - happening more often today, than back-then. Today it happens perhaps by people not using a wad under the ball, or more likely with loose fitting caps that fall off when the first shot is taken.

There has been some 'suggestion' amongst cap and ball shooters, that ring-firing only takes place due to missing caps & this in most likely correct.

I was trying to teach one 'resistant' fellow to use oversized balls + w
thin greased felt wads while he insisted they were too slow loading. He insisted on using undersized balls and holding them in the chambers with crisco shortening - he was from Nevada - I don't know if that has anything to do with his stubbornness or weird ideas. His final e-mail was that "Those old guns don't shoot worth a damn compared to my modern guns".