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BP question

Discussion in 'Blackpowder' started by gasmandave, Aug 16, 2019.

  1. gasmandave

    gasmandave Member

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    I have 2f, 3f, and 4f powder all the same manufacturer.
    If I load 30gr of 3f how can I determine how much 2f or 4f would be the equivalent charge. 4f would be lower amount of grains? 2f greater?
     
  2. gasmandave

    gasmandave Member

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    Would 25 grains of 4f be same or less then 30 grains of 3f?

    How about 35 grains of 2f?
     
  3. Flintshooter

    Flintshooter Member

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    Take 4f out of the equation. That is strictly for priming flintlocks.
     
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  4. J-Bar

    J-Bar Member

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    I am confused about what you are trying to accomplish.

    Start with the premise that blackpowder is always loaded by volumes, not actual mass or weight. Blackpowder is measured with scoops, brass nozzles on flasks, etc. So that means "an equivalent charge" of a different sized powder would simply be the amount of that powder that would fill the measure. Take a black powder cartridge for example: Let's say a .38 Special brass case contains 1 cc (volume) of 2F powder under a particular bullet, and that amount provides sufficient volume to follow the rule about not allowing an air gap between powder and the base of the bullet. The same volume of 3F powder will have a bit more mass, due to less gaps between those smaller powder grains, but could still be called "an equivalent charge" to the 2F powder because it satisfies the golden rule about eliminating the air gap between powder and bullet.

    If you are trying to produce the same muzzle velocity with 3F that you got with the 2F powder, then you would obviously need a smaller volume of 3F in the case, and be faced with using some kind of filler between the powder and the bullet. If this is what you are trying to accomplish, then weigh the 2F powder charge precisely on a scale, then use the same actual weight of 3F to get the same mass of powder. (Assuming here that the same actual "mass/weight" of powder will generate the same pressure curve during burning.)

    This second case seems like a lot of bother to me, so that's why I asked what you are trying to accomplish, and perhaps what firearm you will be using? One of the joys of black powder is being able to throw volumes rather than measuring actual weights. Another joy is not having to worry about 1/10 grain differences in powder charges! :thumbdown:

    So you probably already knew all of this, but I'm just trying to explain why I'm confused!
     
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  5. skeeterfogger

    skeeterfogger Member

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    Yeah, drop the ffff and maintain volume.
     
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  6. gasmandave

    gasmandave Member

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    I was told 2f was rifle, 3f pistol and 4f flash pan. I was wondering if I could sub one for the other and how much.
     
  7. MEHavey

    MEHavey Member

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    Rifle
    2Fg 50cal +
    3Fg 50Cal -
    Note overlap -- whatever works best in that particular rifle*

    Revolver (45/44/36)
    3Fg

    There is no "equation" for equivalency between loads of 2Fg vs 3Fg
    For a given volume/weight, the finer powder will produce more pressure/velocity (mostly)
    but your accuracy may not be best. -- Trial and error to choose

    * Note that I run 3Fg in a 58 Springfield -- Trial and Choice again
     
    Last edited: Aug 16, 2019
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  8. J-Bar

    J-Bar Member

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    I have used 2F in percussion revolvers, pistol cartridges and shotshells with no problems. In a modern gun with modern steel the same volume of 3F should not be a problem. I am not interested in loading 120 grains of 3F in my Hawken. It would probably survive but I don’t see the point.

    I know of a few folks who have tried 4F in percussion revolvers, but it was unnecessarily brisk. Again I don’t see the point. I agree that 4F should be limited to flash pans.
     
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  9. LaneP

    LaneP Member

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    Greetings Gasmandave.

    You can use 2F and 3F interchangeably by volume, but depending on application you may find you are losing efficiency, since 2F is generally considered a better match for long barrels or large volume calibers while 3F is generally considered a better match for shorter barrels or small volume calibers. This is all due to their granulation size and burn rate.

    I load 2F in large volume cartridges such as .45 Colt and .45-70 where I can fill the case through a drop tube and still allow about 1/16" or so of compression of the powder column. But for percussion revolvers from .31 to .44 caliber I use 3F.

    As mentioned, 4F is too fine for cartridges or percussion cylinders and best used only for pan priming.

    I know what you are asking but the answer is not clear cut since to know for instance, how much of one granulation would be "equivalent" to a given amount of the other would take a bit of experimentation and measurement with a chronograph, and would be highly variable depending on the chamber volume, barrel length and bullet being used.

    I have chrono data for volume measurements of 3F using two different charges and two different bullets from my Uberti Walker, I would only need to substitute the same volume of 2F and I would at least have a starting point for how it would affect velocity. Perhaps next week I can try that and post some results.
     
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  10. Jackrabbit1957

    Jackrabbit1957 Member

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    Ok, here are hung up on 4f for flinters, 3f will work in the pan as well as 2f. You really don't need 4f to prime a flintlock. Look at the Brits during the Revolution, did they fiddle with carrying an extra powder flask for priming their weapons? If using coarse powder to prime worked then it ought to work now. 4f has uses such as loading in pistol cartridges or small bore rifles, it's just not a required thing to shoot a flinter.
     
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  11. Flintshooter

    Flintshooter Member

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    This is a fairly new idea to me via the Internet experts and I am in my second half-century of shooting muzzleloaders. I was taught, and it has been the consensus among those I’ve shot with for decades, that wether 2f or 3f is used is determined by bore diameter, not bore length. Usually .45 and under using 3f and .50 and over using 2f. Now it is not uncommon for some shooters to use 3f in everything.
     
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  12. Flintshooter

    Flintshooter Member

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    Agree 100% with what you say about using 3f or 2f to prime. However I think 4f as a primary charge is a bad idea unless it’s a really small charge. Like squirting a dryball put.
    The smallest thing I shoot fairly regularly is a .32 flinter with a 46 inch barrel and what I shoot most often is a .65 smoothbore so maybe I’m bias.
     
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  13. wmgeorge
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    wmgeorge Contributing Member

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    I think I see what he is saying. 2F is more coarse than 3F, so just scooping up by volume 70 gr of 2F vs 70 gr of 3F since the granules of the 2F are not as close together as the 3F it would seem the 3F would be the greater load. That was proven by someone else on here posting using 4F which gave a much hotter bang, vs the same volume of 3F.
    Therefore you should reduce by volume the charge going to a smaller granule, to be correct. I think in a modern gun its makes no difference.

    As far as 4F for priming, perhaps the touch hole on the older rifles was larger and when they were downsized for modern guns and safety the 4F came into use?
     
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  14. Jackrabbit1957

    Jackrabbit1957 Member

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    That may be right as far as touchholes are concerned. Most seem to run around .040 ish, I opened up mine to .070 in a stainless liner. I find ignition was improved quite a bit.
     
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  15. StrawHat

    StrawHat Member

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    Actually, neither British nor Colonialists used a separate priming powder, just what was in the cartridge or the horn. Back then, powder came in one variety, whatever you could get from the sutler or powder maker.

    You either had a day horn, usually small and holding enough powder for a days hunting or you might have a supply horn that could carry as much as a pound of powder.

    Carrying a separate priming horn is a modern concept.

    Kevin
     
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  16. randys

    randys Member

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    Kernels of 4F are smaller diameter than the vent holes of factory cones on older Uberti/Colt, Pietta, ASP, and ASM revolvers. Powder dribbles out as you are loading. Not goodness, but you can adjust for it in many ways.
     
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  17. wmgeorge
    • Contributing Member

    wmgeorge Contributing Member

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    I'm guessing they only had one size of powder 100-200 years ago. When it was discovered that 4F gave better ignition thats when the change was made in modern times.
     
  18. noelf2

    noelf2 Member

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    3f works for everything. Best to keep it simple.
     
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  19. Loyalist Dave

    Loyalist Dave Member

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    OK so you had some old information that's been taught for a while, mixed with what actually is going on....

    First as the replies have stated, 4Fg is most commonly used as priming powder in the pan of the flintlock. You will find some folks using it in very small caliber pistols, and using it to reload .22 LR rounds for end-of-the-world-disaster training, and such.

    YES they did actually have granulation sizes for gunpowder [black powder] as early as the 18th century. So there was 1F, 2F, 3F and etc granulation system in place.;)
    Today, when you see something like 3Fg the little g means that the granules are coated with graphite. This helps to keep them from breaking down into smaller bits, keeping "dust" down, and making them a teeny bit more resistant to moisture. NOW whether or not the frontiersman had a choice when he was at the trading post to refill his horn..., that's a different question. :D

    You can, as folks have written, swap between the two powders by using the same powder "measure" which actually gives you the same volume of either powder. Should not be a problem for the rifle or pistol.

    NOW... I think..., my wife says this is dangerous for me..., you're asking about the power of the powders vs each other? In other words, IF you use 80 grains of 2Fg, and you then use the same powder measure setting for 3Fg, what happens? The old rule of thumb is you will get about a 10% increase in velocity. So you REDUCE the 3Fg charge by 10% when switching to that from 2Fg. (In this example you would subtract 10% which would be 8 grains, and round to the nearest setting on your measure, which would be 70 grains for 3Fg) That gives you usually, a very similar muzzle velocity for your projectile, and since most of us use fixed sights, it should put the projectile pretty much in the same spot on the target. At 50 yards you probably won't see much difference, and a deer won't know, but at 75+ yards, that change in a point of impact might mean the difference between dropping the deer in it's tracks (or winning a match) and you needing to spend a couple hours tracking the dying deer. o_O

    In the 30 grain example in your original question, going from 30 grains of 2Fg would mean setting your measure at 25 grains when using 3Fg

    I hope my guess at what you were asking was right.:thumbup:

    LD
     
    Last edited: Aug 17, 2019
  20. wmgeorge
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    wmgeorge Contributing Member

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    Dave Excellent info, thanks for posting.
     
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  21. robhof

    robhof Member

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    I've used 4f in my ROA's on many occasions with no problem, except with equal volume, I got a hotter load, I've also used 2f when I ran out of 3f, that resulted in a slightly milder shot with equal loading, if you're using a moderate loading, then all are usable, but the 2f and 3f are preferred and the only way to be sure is to target shoot the loads from a rest and adjust till you get equal loads.
     
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  22. robhof

    robhof Member

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    Actually there are fine examples of antique priming horns/flasks, usually from estates of well to do individuals that competed, they actually did have gun matches back in the flint days and even then they squeezed every bit of advantage they could get out of their guns, so priming powder did exist, practical in the day NO, but it was to some extent available.
     
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  23. gasmandave

    gasmandave Member

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    @Loyalist Dave that was the type of answer I was hoping for. Puts mind to right thinking. Thanks.
     
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  24. StrawHat

    StrawHat Member

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    I have seen very few authenticated sets of horns. They exist, no question, but as you pointed out mostly among the wealthy. Same thing for the various sporting powders. Quite common in England and Europe, not so much in the Ohio frontier.

    Kevin
     
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  25. arcticap

    arcticap Member

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    It's hard to answer such a question without knowing the length and caliber of a barrel and using a chronograph to determine velocity.
    There are velocity tables in some reference books such as the Lyman Blackpowder Manual.
    But at some point after the early editions they stopped publishing data for 4F powder.

    I would like to add that it's possible for a person to develop a custom load of a mixture of powders that probably should be loaded on an individual basis.
    That is, the amount of each powder loaded should probably be loaded separately and in the same order each time.
    For instance, a person could develop a load using 10 grains of 4F, 30 grains of 3F and 30 grains of 2F if they wanted to and they found that it worked well for them.
    As far as I know, there shouldn't be any safety reason why 4F can't be used in the bore as part of the main charge as long as all safety precautions for the barrel's caliber are followed while working up the load and the barrel is in good condition.
    But that it just my own biased opinion based on nothing more than common sense.
    Of course, a chronograph or range testing could be used to verify the results of the experimentation for consistent velocity and accuracy, based on your individual barrel.
     
    Last edited: Aug 18, 2019
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