Graphite Coated BP for Ejection Charges: To Use or Not To Use…

I'm researching BP for HPR ejection charged. I've been advised to alway use FFFF when available but the FFF and FF can be used. I've seen discussions on the graphite coated BP. There's never been a truly clear reason to use or not use the graphite.

So do you advise for or against graphite coated, and why?

It's my understanding that the veneer of graphite on the surface is to keep it from sticking to each other. That would make it easier to pour, measure, etc. I don't know if there has been a study to show that BP with graphite has a performance or residue difference from untreated BP.

I'm not sure it matters that much one way or another.

Greg

Graphite glazed is designated by a G after the F size code. (FFFFG, FFFG, etc.) The G series works fine and is less dusty for a more consistent grain size. The graphite also reduces the chance of static discharge as the graphite is conductive.

I don't even think 4FA grades are sold to the general public. My understanding is that bp is an explosive and FA grades are sold for firework use, so they require a ATF license. The FG grades are used for guns and since they are exempt for sporting use, gun shops will generally only sell FG grades. I think I have seen online places selling FA grades without a license but the min. order is 25lbs for a max. of 50lbs. (which is way too much)

I have not seen any issue with 4FG blackpowder used in ejection charge. 3F or 2F will burn slower and so you may need to use a little more when calculating ejection charge amount to account for the slower burn. The graphite is there to make the powder easier to pour.

Some information: https://www.skylighter.com/fireworks/making-fireworks-projects/blackpowder-fireworks.asp (I don't know if this is allowed, please let me know if it is not)

The link contains information about various grades of bp and that FA/FG is not the same!!

The BP available locally is 4F. No g on the label and the associate says it was not graphite coated. So I needed to know for certain the advantage or disadvantage of each.

You might want to find out the granulation of the bp, and if the 4F means 4FA or something. That is because 4FA is NOT the same size as 4FG. In fact 4FA is the same size as 2FG. You will need 7FA if you want the same size as 4FG.

4F or FFFF is exactly what we use for ejection charges. Most common brand found at Sporting/Outdoor type stores is Goex.

Look like this generally, but packaging has been known to change. Runs between 18.00-25.00 depending on who's selling it.




the plain ole 4F or FFFF is what to get! You can use others, but this is the preferred if you can get.

All commercial black powder is graphite glazed.

Kevin

Nessalco said:

All commercial black powder is graphite glazed.

Kevin

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BINGO! We have a winner! The normal use of FFFF is in the flash pan of muzzle loading flintlock rifles and pistols. Because the smaller grains burn more rapidly than the large, they communicate fire better as well.

I have only ever used FFFFG. Very easy to use.

To those of you saying that all commercial BP is graphite glazed, do you have a point of reference?

I know the BP for sporting use is graphite coated, but the FA grades are not graphite coated. Thing is FA grades are not normally sold to the general public, and most places require an ATF license unless you can certify that you are going to use it in bp guns. Ace Pyro sells commercial non graphite coated bp (FA grades) and will sell you 50 lbs if you can certify that you will use it for bp guns and not fireworks. But their minimum order is 50lbs and that's way more than 100 rocketeers will ever use in 20 lifetimes. But also FA grading scale is different than FG grading scale. FG grades are always graphite coated and FA scales are not. If you somehow came across a shop selling FA grade bp then you have to get 7FA because that's equivalent to 4FG. If you get 4FA then it's more like 2FG and as a result you'll have to change the charge amount to compensate.

But most gun shops won't sell FA grade bp because if you use them in a gun, it's going to lead to performance issues (2FA bp for example will not function well in a rifle because it is more like cannon grade bp).

Bat-mite said:

I have only ever used FFFFG. Very easy to use.

I'm not certain about the "all" part but here is my point of reference.

To those of you saying that all commercial BP is graphite glazed, do you have a point of reference?

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The Chemistry of Powder & Explosives, Terry L. Davis, PhD https://www.amazon.com/dp/0913022004/?tag=skimlinks_replacement-20

https://www.amazon.com/dp/0929931149/?tag=skimlinks_replacement-20

As I understand it, the graphite glaze acts as a dry lubricant and helps keep the particles from sticking together and forming a cake. Black powder is hygroscopic https://www.merriam-webster.com/dictionary/hygroscopic and easily clumps up in humid air. That's probably where the old adage came from as in, "keep your powder dry". :kill: