Pistols at this time were not used with a 'supporting hand'. This stemmed from the days of the flintlock pistol and the flash from the pan. Military and naval flintlock pistols were often used with the lock towards the sky, mainly to ensure the intitiation of the charge. There was no sight on the barrel. For military use, often the 'other' hand was also doing or holding something else. There was also duel 'etiquette' which dictated that pistols be held in just one hand.
This tradition continued over the change to percusson and the gradual introduction of revolvers. Despite the provision of sights, it seems they were not often used and pistols remained a close-quarter weapon - "point it in the right direction". It is perhaps to maintain this tradition that the 'cylinder gap' theory was started. Without a doubt, there were some pistols that splattered hot gas and even lead fragments, given the state of poorly maintained or over-used pistols of the period, but I suspect that this did not apply to the better makes.
We've had our differences of opinion but should you ever visit Antietam, Harpers Ferry or Gettysburg you're invited to my nearby home to shoot many things old and new that will put a smile on your face and leave great memories. I have a pretty nice display of CW relics I have dug here you might find interesting also. BTW I'm a great fan of the Spitfire and the Rolls Royce Merlin. Got fly behind one many years ago in a P-51, although it was built here under license by Packard. The sound of that beautiful (it's a pretty engine) V-12 is pure music to the ears.
Bringing the