Different Power Granulation Burn Rates

[roundball]

A run of black powder is made and a lot # plus a date code are assigned.

Towards the tail end of the manufacturing process...of this same single "lot" of blackpowder...some means of grinding / breaking up the large cakes of BP into usable sizes results in blackpowder being produced / screened / separated into various size "granulations": 1F, 2F, 3F, 4F, 5F, and 7F. (possibly more I'm not aware of but you get my point)

And we know equal volumes of different size granulations have different burn rates with the finer granulations burning faster, because of the increased number of kernels and surface areas to burn simultaneously...ie: 50grns of 7F powder burns much faster than 50grns of 1F, etc.

Accuracy with a Flintlock has a direct relationship to ignition speed of which priming powder speed is a component...and while the average human being might not be able to tell a difference in ignition speed between priming with 4F vs. 2F, knowing scientifically that the 4F is faster, I'm puzzleled as to why more people don't use 4F prime...particularly since it's basically identified as priming powder in the first place.

:hmm: Is it because 4F is not readily available locally, and to order one can of 4F would make the overall cost prohibitive, so people tend to accept using other powders to prime with?

:hmm: Is it because loading from a horn people think that also using a pan primer would be too much trouble?

:hmm:

 

[dlemaster]

Well, I hope this doesn't turn into something like the lead/leather wrap thing, but here goes.
I use to use 4F for priming, still do on rare occasions to get it used up. I could find nothing to prove a seperate priming powder was used in the period and it didn't take me long to figure out that it was one less container to carry or have to keep full. I've found that 3F seems to work as well. Then I read an artical in JHAT about lock time (written by Pletch I believe) and I noticed that the difference in lock times between 3F and 4F was insignificant. So I quit worrying about it.
OMMV

Regards, Dave

 

[roundball]

"...Well, I hope this doesn't turn into something like the lead/leather wrap thing, but here goes..."

I agree and it absolutely should not...if it does I'll volunteer to ask Claude to just delete the thread.

I've always used 4F simply because "the industry" says that "it's faster", whether or not I can tell it when I fire the rifle...yet, many people do not use 4F so I'm trying to get a feel for the legitimate reasons why...maybe I'm wasting my time worrying about it too.

(in fact, it might even be better suited to a 'poll' type question)

 

[Landngroove]

For me it is a matter of convenience. FFFG for the main charge, and in the pan. I don't have to mess with another can of powder. :grin:

 

[renovato]

I wonder if 4F isn't still around simply because of tradition? Maybe in the old days, powder wasn't as consistent, or locks didn't spark as well or something. Maybe the earlier factory replicas didn't have the high quality locks we have today so the powder companies cooperated with them and made "priming powder"? I don't really know and I'm too new to flint to speculate much.

I've sifted some fines from my 3F and used it as priming powder. I've also used 3F to prime. I can't tell a difference in ignition. The only difference is that sifting the fines out of my 3F made the 3F a little more consistent, so I'm trying to find a way to use up the fines now.

 

[Old Ironsights]

I've sifted some fines from my 3F and used it as priming powder. I've also used 3F to prime. I can't tell a difference in ignition. The only difference is that sifting the fines out of my 3F made the 3F a little more consistent, so I'm trying to find a way to use up the fines now.

Works good in a .38sp case with a heavy soft lead bullet... hits right around 500fps out of my .38/.357Winchester 1892 clone.

My pellet gun is louder than my 5gr4F/filler/180gr 75ft max "catsneeze"/"coonwhacker" load. :hmm:

But I haven't found a good ML use for it.

 

[Mad Monk]

Roundball,

4F powder does indeed burn faster than 3F in the lock pan. But only marginally faster. It take some facncy electronic gear to show the tiny bit of difference.

The thing with 4F vs 3F in the pan is that given the greater amount of surface area of the 4F (compared to 3F) the 4F will pick up moisture faster and in a greater amount.

Understand that what is sold as 4F today is mainly what is nothing more than process tailings from the powder screening operation. No longer a specific size range. This tends to worsen the thing about amount of moisture picked up and the speed at which it does so.

So selecting 3F as the lock prime when you also use it in the main charge is a bit of a trade. You give up a wee bit of lock speed for a longer useful life in the lock pan.

 

[Russianblood]

I have noticed that my priming pan doesn't turn to goo with 3f as fast as it does with 4f. I still primarily use 4f for priming under controlled conditions but if it's extremely moist out, I'll be using 3f to prime.

 

[rabjr]

I have honestly never seen 4F. Can't say I spent much time looking for it either. I have 3F and know I can get get 3F so it was just a no brainer for me to use 3F as a prime.