BP burn rate chart

[GregLaROCHE]

Is there a chart available, that shows all the relative burn rates, of all the major producers of BP in the world?

[rfd]

nope, no need for that. here's the bp "burn rate" as compared to smokeless ...

[greenjoytj]

Which smokeless was that, a slow burning rifle powder or a very fast pistol powder?

Where would a quality BP 2 & 3 fg be if it was assigned a place on the Hodgdon’s burn rate chart?

[rfd]

it's not bp's "burn rate" that matters, it's about how quickly will it ignite.

[rancher1913]

black powders burn rate is very high, thats why its an explosive rather than a propellant like smokeless. stop trying to compare apples to oranges.

[rfd]

bp is not exactly an explosive, even though it's classed as such, it just has a warp speed burn rate no matter how fine or coarse a grain.

[GregLaROCHE]

All explosives are really a fast burning. Even C-4 plastic explosives have a burn rate. I used to know it from my military service, I don’t remember exactly and don’t want to quote something inaccurate. Maybe it’s around 20,000 ft/sec.

My original question was about comparing different back powders. I want to change from one to another and don’t want to over pressure the gun. Isn’t there something like the charts for smokeless, that compares the power of different powders. My gun is over 150 years old and I don’t want to take any chances.

[rfd]

if it's real bp yer using, there won't be any "over pressure" in changing the grain size. given the same volume throw, there is a "power" difference between different grain sizes, i.e. 1f to 3f. the finer the grain, the more active powder within the same powder throw volume. 4f is relegated almost always for flinter pan powder. there is also a "power" difference between different brand bp "recipes" where swiss definitely has a tad more kick than goex. for a modern steel bpcr or ml gun, 1f to 3f in the case or down the tube is no big deal. however, for the lower grade metal of a hundred or more year old gun, that's a different story IMO. i have such a gun, a roller, and there is no way i'm going to build cartridges for it until a qualified 'smith that i trust will first check it out, and even then i'll proof the barrel before i get up close 'n' personal and put a finger on its trigger.

[Randy Bohannon]

Low order and high order explosives <2000 fps low order > 2000 fps high order. B/P is low order < 2000 fps.

[rfd]

yes, real bp has a slow decomposition rate and low brisance.

[John Boy]

Greg ... why do you want to know “burn rate” of BP and what caliber firearm do you plan to shoot BP reloads. All the makers in the world? There are only 3 makers of the powder available in the US.... Goex, Wano - makes Schuetzen and Swiss.
BP is a low briance burning powder and does not explode like smokeless. It does not have a burn rate. It deflagurates.

[GregLaROCHE]

I am in France. There are Vectan powders and Swiss available. The gun I just bought is a 1866 Chassepot. It’s known as a needle gun, because a sharp needle pierces the back of the paper cartridges and strikes the primer that is inside the cartridge. For this to work properly. The paper cylinder that forms the walls of the cartridges has to be full of powder, packed tightly. That’s what keeps it ridged and strong enough to support itself, when the needle pierces it. The total length of cartridge and boolit must be exact too.

I bought this gun from a person who has shot it in competitions for forty years and as a binder with all the different loads he tried and the targets it produced. One problem is that the lowest elevation setting on the rear sight is for 350 meters. He changed the front sight post to raise it and was shooting at 100 meters. My club has a max range of 50 meters. My hits were two feet or more high. He was using an old powder called mousqute. This powder may be approximate to the original powders. It is very dirty and fouls the chamber quickly. I think there is a great difference in the size of the grains in it. Some are as small as dust. Another powder is called Chase or hunting. It also falls into the same type of powder, but I don’t know the differences. Then there are the newer powders called PNF1, PNF2, PNF4 and then the Swiss powders. I use PNF2 in my original Charleville, but only around half the original charge. It works well in the Charleville because it burns clean. I would like to use PNF2 because of is clean and complete burning of the paper left in the chamber.

I want to choose a powder that is clean burning and less powerful then the PNF2. Maybe PNF1. If I have to use less charge, I will try filling up the rest of the paper cartridges with semolina, to arrive at the correct compaction and overall cartridge length. The other option I have is to file down the rear sight, but I hate to change an antique rifle. Also maybe trying a heavier boolit. This is why I am trying to find something that compares the burning rates of BP.

Thanks

[John Boy]

Greg, the Vectan reloading table for black powder firearms - cartouche paper lists the loading data for the Chassepot to have a powder charge of 3.5 to 4.0 gr of PNF1
http://www.vectan.fr/UK/reloading-charges