Spgsamuel, I know it has been some time on this topic but, I was trying to find your resources pertaining to the Giffard Air Rifle.
"Basically at the end of the first world war around 1841 the allies commissioned around 300 of these to be manufactured and used as one of the first silence type weapon's. The gas chamber contained a substance called Carbonic acid, this is a liquid under pressure, when fired a small amount of the liquid was ejected into the firing chamber which would expand rapidly into a gas propelling a small bearing. Its one of the first guns of its type, if you look at veterinary rifles they still use a similar method for firing darts they have a similar gas chamber, it is both silent and effective although the substance they use now is no longer Carbonic acid as I have found on online resources related to modern gas weapons and Carbonic acid.
It was not the best weapon. The bearing were about 0.5cm's and the barrel was breach loading meaning a bearing needed to be dropped in the barrel tip end every shot, it you aimed down the bearing would start to come out and the barrel pressure would be very low. It was designed to be used in this manner as the Carbonic acid chamber had about 4 to 5 good shots before a new one needed screwing on.
So basically the gun would be held pointing up to prevent the bearing from rolling down the tube and it would have had an effective range of about 20 feet ideally only a head shot would be lethal as its bearings have such a low magnitude, being so small. However, the design was such that an unsuspecting soldier could be shot as much as 3 times by simply holding the gun upright and popping in another bearing, it would have taken that long for a rifleman to sort himself out, whilst being shot.
They were not considered successful or particularly useful. As such, they were given to decorated officers as gifts for their service. However, they did pave the way to silenced firearms and were the world's first gas-powered firearm and I think that makes them pretty dam cool and worthy of a late post.
I suspect the magnitude and speed match a .22 firearm. Due to the style of the weapon potential energy was lost rapidly giving it a very small range as the bearing weight would have slowed it. An explosive charge gives a firearm lots of potential energy allowing it greater penetration than it would have, the energy from the combustion is moved into the bullet so it travels with stored energy allowing greater penetration. Gas power gives weapons very low penetration as the energy is more kinetic and less barrel pressure based most of this energy would be absorbed on contact with the target. Technically the speed and power of the bearing relatively should be around .22 cal but I honestly would call it a lot less as its propellant is inferior as is its munition, so you're basically looking at a very bad .22 pistol."
Thanks