Determining the powder charge

[Brian the Brit]

In 'Powder and Ball Small Arms', The Crowood Press, (1998:15), Martin Pegler says:

"It is interesting to speculate how early hand-gunners determined the correct charges for their weapons other than by a sometimes lethal process of trial and error. A rule-of-thumb method which was still in use in the percussion era was to take a musket ball in the palm of the hand, and pour powder over it until the ball was totally covered by a pyramid of powder. This was regarded as a reasonable starting point for determining the size of the charge."

So I thought I'd have a go.

Depending on to what extent I cupped my hand when pouring the powder, the charge for my 20 bore (.575" ball) flintlock pistol measured between 85 grains vol. (palm flat) and 40 grains vol. (palm cupped).

I suppose 85 grains wouldn't be too unreasonable for a rifle or musket in this calibre (if a bit on the heavy side) but I certainly wouldn't want to shoot 85 grains in a 200 year old pistol.

Can I presume that the method described above only applied to long guns and if not, can anyone tell me what the estimating technique was for pistol charges in the old days?

 

[Mike 56]

If i was looking for a load i would use a loading manual. That does not seam like good way to figure a load. Sounds like a myth to me.

Mike

 

[mazo kid]

I have not heard that "rule of thumb" applied to pistol charges. 80 grains is a HUGE load in a pistol and totally unnecessary in such a short range gun. I personally would start at around 20 gr. and fire a few shots to see the group. Then keep increasing the charge by no more than 5 gr. at a time until a maximum of around 40 gr. Somewhere in the mix, you should find the most accurate load. With that determined, you can then experiment with different patch thickness.

 

[Deschain19]

Thats a neat bit of history. I understand the question, you aren't looking for what to load today, you are asking what they would have used to guess way back when. Glad I'm not that one that had to do the experimenting!

 

[Zonie]

Like many others, I've heard of the "cover the ball" method being used in the past but I was always under the assumption that it was used for rifles only.

A few years ago someone wrote an article for Muzzle Blasts (NMLRA magazine) in which he tried to determine if this method would work.

To get a better idea of the range of powder loads that would be expected he used his hand, his wifes hand and his teen aged daughters hand and poured the powder many times to get a fair average.

It turned out that the average of the loads was around the same value that many folks take as a starting load. That is, the old 100 X bore size rule where for instance a .50 caliber would be .50 X 100 = 50 grains or .40 X 100 = 40 grains.

I suspect that "back in the day" the buyer of a pistol would take the word of the gunsmith or gun store owner where he bought his gun to get a "recommended" powder load for his pistol.

I'm also going to guess that the recommended powder loads given would have been relatively "light" for a pistol.
IMO, it is only with the advent of modern high powered cartridge arms that the "Magnum" or "Dirty Harry" mind frame has developed.

If we can believe Dixie Gunworks Catalog, the standard Military loads for some pistols were:
.67 cal Tower Flint Pistol = 35 grains
.58 U.S. Springfield Model 1855 pistol = 40 grains
.54 cal U.S. Pistol Model 1819-1842 = 35 grains.

 

[Mike 56]

Those loads are about right i looked up a PRB load for a .54 cal pistol with 1-30 twist and a 8 inch barrel. A 35 grain load of Goex fff had 4,600 psi and went 813 FPS at 25 yd. A 50grain load had 9,100 PSI and went 914 FPS at 25 yd. That's a lot more pressure a 100 FPS.

Mike

 

[Coot]

I do not know about "back in the days", but as Zonie pointed out, the Dixie catalog has a lot of "standard" loads listed. A frequent starting point for long arm loads is to use one grain of powder for each 1/100 of bore (.40 cal = 40 grains, .50 cal = 50 grains) and to move up & down in 5 grain increments to find what the gun likes. Looking at a number of pistol loads, it seem that using 1/2 of what a similar bore longarm would take gets close to a number of pistol loads. :hmm:

 

[Raider2000]

I do not know about "back in the days", but as Zonie pointed out, the Dixie catalog has a lot of "standard" loads listed. A frequent starting point for long arm loads is to use one grain of powder for each 1/100 of bore (.40 cal = 40 grains, .50 cal = 50 grains) and to move up & down in 5 grain increments to find what the gun likes. Looking at a number of pistol loads, it seem that using 1/2 of what a similar bore longarm would take gets close to a number of pistol loads. :hmm:

Sounds about right, I remember my Great Grandfathers 1851 Colt Navy .36 caliber, & my grandfather would only load 18gr. FFFG into it which yielded very good shots & was able to dispatch a Wolf quite nicely on occasion.

Today my Round ball load 2 of my .44 caliber C&B revolvers shoot their best groups with 22gr. FFFG & only appreciates a 30gr. load with a heavy conical.