So your telling my it takes 33 grains of BP for a 45 Colt! that a ton of powder!
Actually, the charge will vary slightly depending on the brand of Black Powder you use.
Unlike Smokeless powders, where the manufacturers go to a great deal of effort to make lot after lot exactly the same, Black Powder made by various manufactures does not all weigh the same.
A bunch of years ago I made up a chart of the actual grain weight of the various brands of Black Powder I use in my standard loads.
The column on the left indicates the standard sizes in Cubic Centimeters of the Lee dippers. Then the other columns are for the various powders I have used over the years. 2.2CCs is the charge I use in both 45 Colt and 44-40. If you look across the row you will see that the heaviest powder was Elephant FFg, weighing 37.5 grains for a 2.2CC charge. The lightest is Goex FFg, weighing 32.3 grains. Currently I use Schuetzen exclusively, and the charge weight of 2.2CCs of Schuetzen FFg is 33.3 grains. I made this chart up for reference only, just to get an idea of the actual weight of my charges. I would not be surprised if the weights had changed a bit by now, because Black Powder manufacturers do not go to the extreme lengths that Smokeless manufacturers do to keep their powders consistent from lot to lot. Also, if I stuffed a little bit more powder in, that would affect the charges too. These are just my standard loads. 4.3 CCs of Schuetzen FFg is what I use in my 12 gauge Black Powder shotgun ammo. Also, as has been state several times, a couple of grains plus or minus of Black Powder does not matter a whole lot.
Regarding modern powder capacity vs the powder capacity of the old Balloon Head cases: On the left in this photo is an old Balloon Head 45 Colt case, on the right is a modern 'solid head' 45 Colt case. I cut them in half for this photo. You can clearly see there is a little bit more powder capacity in the old Balloon Head case than in the modern case. I'm not exactly sure when Balloon Head cases stopped being made, but for most of the late 19th Century, and probably a few years into the 20th Century, that is the way cartridge cases were made. So clearly a little bit more powder could be stuffed into the old Balloon Head cases than modern ones. Oh, I know there are guys who jam 40 grains into a modern 45 Colt case, but they are compressing the dickens out of it to get that much powder in there. Plus, I have no idea what brand of powder they are using, as my chart shows, 40 grains might be easier to stuff in, depending on the brand and granulation of powder you are using.
Now, compare the old Balloon Head cases to these. This is 45 Colt and 45 Schofield ammunition the way it was first manufactured by the government run Frankford Arsenal in 1873-1875, and perhaps a bit later. The cases of this ammo were copper, not brass. The priming system was different than modern primers. The priming material was deposited on the bottom of the case, then an Anvil Plate with two holes in it was pressed down on top of the priming material and crimped in place. The crimp at the bottom of the cases is what kept the Anvil Plate in position. When the firing pin struck the center of the copper case, the priming material was compressed and ignited. The resulting flame traveled through the two flash holes in the Anvil Plate to ignite the powder charge. Looking at the rear of the cartridges, they appear to be rim fire cartridges, but they are not. This early system of priming was a centerfire system, called Benet priming after the head of the Franford Arsenal, who invented it. Anyway, my point is the old Benet primed, copper cased shells had slightly more powder capacity than the slightly newer Balloon Head cases, and these were the ones that actually contained 40 grains of Black Powder.
This is a box of 45 Colt cartridges from my cartridge collection. I positioned three rounds from the box next to a modern reload of mine. You will notice these cartridges only contain 30 grains of powder. The army had decided by this time (1874) that the original charge of 40 grains of powder was just too much in a revolver, so the charge was reduced to 30 grains. The extra space was taken up by cardboard wadding.
The dreaded air gap between blackpowder/ bp substitute and a projectile…
There is enough historical, anecdotal evidence that an air gap between black powder and projectile can cause barrel bulges or barrel rupture that one should not dismiss the concern completely. But there are a dizzying number of variables involved. Caliber, weight of projectile, volume of powder used, brand and granulation size of the powder, amount of the air gap itself, etc. Isolating and testing each combination of variables is beyond my means and interest.
I know from personal experience that a scant air gap in a .38 Special blackpowder cartridge causes no problem. But I am not going to encourage anyone to ignore the presence of a gap. I view the old rule of thumb, “ don’t allow an air gap between powder and projectile” as an easy safe way to avoid potential dangers that could be caused by all those other variables.
You pays your money and you takes your chance.
I heartily agree. There is plenty of anecdotal evidence to show this is not 'nonsense'.
The theory is, since Black Powder is a true explosive, not a progressively burning propellant like Smokeless Powder, if an air gap is left in the cartridge with Black Powder, the powder can burn partially or fully before the bullet gets a chance to get out of the way. This can cause pressures to skyrocket.
Clearly there are many different variables. A friend called me up one day saying he would like to load some Black Powder cartridges using hollow based bullets, and wondered if the small pocket of air created would be a problem. I said probably not. Those 30 grain cartridges pictured above have wadding taking up the extra space inside. the 45-70 cartridges used by Cavalry for their lightweight Trapdoor carbines only had 55 grains of powder inside. The extra space was taken up by wadding. I would assume the government did this for a reason, it was extra work, and increased the cost, to fill up the empty space with wadding.
I too err on the side of caution. There is never any airspace left in any of the BP cartridges I load, and I load a lot.
