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Fastest speed you can get with bp

Discussion in 'Blackpowder' started by tank mechanic, Mar 5, 2010.

  1. tank mechanic

    tank mechanic Well-Known Member

    What is the fastest speed a bullet can achieve with the use of black powder as a propellant?
  2. Cosmoline

    Cosmoline Well-Known Member

    My understanding is the max is shy of 2,000 fps or so. I believe it was a really big deal when the first smokeless rounds started exceeding that threshold.
  3. BHP FAN

    BHP FAN Well-Known Member

    ...and we care,why? most don't shoot, say, .45-70 for the velocities we can get. also,with serious calibers,it's not about velocity, so much as retained energy - of which, there is a bunch with a 405 gr. bullet, even at a leisurely 1,000 fps.
  4. tank mechanic

    tank mechanic Well-Known Member

    Thanks for pointing out once again why the highroad sucks BHP FAN. God forbid someone wants to know something that might not be practical.
  5. david58

    david58 Well-Known Member

    I think a .40 with patched round ball can hit 2000 in a long barrel. I know little of the saboted inline stuff, maybe they will hit a tiny bit faster. Dunno why I'd think that....patched round ball has always worked well for me, and the little 40 I had was deadly on mule deer.
  6. higene

    higene Well-Known Member


    With PRB speeds run from 1200 to at or about the 2k mark. With a .32 1800 fps with a 45 gr prb is about 22 mag but short of a 22 Hornet. A traditional sidelock or flintlock .50 195 gr or.54 225 gr PRB can get 2k with 110 gr of fff 777(Warning: we're all gonna die puttin' that much powder in these old guns). A 30-30 gets 2000 from a 170 gr jfp. A 30-06 gets 2700 from a 165 whatever. That puts the BP guns in 50 and 54 (Probably .45 but I haven't chronoed one) between a 30-30 and a 30-06 for power Not for speed. The hard knock on PRBs is that they fall on their a$$ shortly after 75 yards due to a poor ballistic efficiency. Hence the movement to conicals. After that we re-invent more efficient priming and the 45-70.

    The magic of large bore conicals in the 400-700 gr class is that they will shoot at 800 to 1000 yards with the center fires, rainbow trajectory not withstanding.

    Lyman and Thompson Center have manuals online if you want to do your own research.

    So that's everything that I know about BP speed and ballistics. Take what you want and make smart remarks about the rest.


    Tacky remark to be added after my nap.

    Last edited: Mar 6, 2010
  7. arcticap

    arcticap Well-Known Member

    Traditions has a sample load chart indicating that a .40 caliber saboted bullet weighing 180 grains can attain a velocity of 2391 feet per second from a .45 caliber muzzle loading rifle with a 150 grain powder charge. But that's probably with a substitute powder.


    Ultimate Firearms produces a strong custom inline rifle that will safely shoot 200 grains of powder. Using a magnum rifle primer for ignition, they claim that all of the powder will completely burn in the first 9 inches of the barrel. I'm not sure how fast black powder can push bullets out of their guns but they also claim velocities slightly under 2400 feet per second with 270 - 300 grain bullets. Even if they're loading with Pyrodex pellets, Swiss black powder just might produce similar velocities.

    Last edited: Mar 6, 2010
  8. BHP FAN

    BHP FAN Well-Known Member

    Tank, Cosmo had already answered your question,I was merely pointing out what is [to me] a more important consideration,when working within the constaints of black powder.I suppose I could have phrased that better.And....the High Road doesn't suck...after all, you're here.
  9. Jefferson Herb

    Jefferson Herb Well-Known Member

    thr bp velocity

    It does'nt suck it blows[boom!!!] There are always going to be throwbacks who just want to feel self reliance and will make their own powder ,guns etc.
    I don't have a spark model yet,[give me time]but run the gauntlet.After all there are threads from Flint,air to class three stuff;I don't have to like everyones toys but I'm jealous of the ones who have unlimited funds.
  10. BHP FAN

    BHP FAN Well-Known Member

    I'm jealous of any toys I don't personally own...
  11. RyanM

    RyanM Well-Known Member

    The theoretical fastest is probably higher than anything you can get from a muzzleloader.

    The fastest velocity with smokeless I've heard of in a sorta normal firearm is 6,616 fps. It was a wildcat .30 cal using .50 BMG cases, shooting saboted lightweight steel projectiles (it was a fragment simulator, not a regular gun). But IIRC, the theoretical max is 8,000 or 10,000 fps, which requires a gun with an internally tapering barrel (to keep pressures high) to achieve.
  12. tank mechanic

    tank mechanic Well-Known Member

    Thanks for the interesting replies.

    Just to clear the air, I sent BHP Fan an apology PM so hopefully there are no hard feelings.
  13. Cosmoline

    Cosmoline Well-Known Member

    It's actually a really interesting question, because one would assume that as a propellant you could keep adding more of it to increase the speed. But there really does seem to be a "wall" when it comes to black powder. As arcticap's chart shows even with more modern BP loadings you are hard pressed to get far into the 2,000's.

    From reading about the 19th century African explorers, my understanding is that the inherent limitations of BP forced them to adopt larger and larger bored weapons. Going faster was not an option beyond a point, even with brass cartridges and centerfire primers. So the slugs had to keep getting bigger. That was only changed with nitro powders and after that point in the 1890's the 8 bore, 4 bore, paradox guns and other mega-bores faded from the scene to be replaced with "small" NE doubleguns and high velocity military type rounds.

    But I've never heard a scientific explanation for this. It seems you can even fill a bench rifle's barrel with BP and still not get much of a velocity increase.
  14. RyanM

    RyanM Well-Known Member

    Scientific explanation: a bullet can only travel as fast as the propellant gas can, and an expanding gas can move, at the absolute fastest, at the speed of sound inside that gas.

    This is also the difference between detonation and deflagration. A detonation means the gas moves at the speed of sound (in the exploding gas, not in air, so blast fronts are generally considered supersonic), while a deflagration means the gas is moving at any speed less than that (but a deflagration can be supersonic in air, too). TNT has a speed of sound of around 22,000 fps, which is why it blows stuff up a lot better than smokeless powder.

    So black powder gas has a higher speed of sound than air, but is lower than the speed of sound in smokeless powder gas.

    That's also why airguns top out at relatively low velocities (the speed of sound increases with pressure and temperature, so airguns can exceed the speed of sound in regular pressure and temperature air. Especially spring piston ones, since they heat up the air as well as compressing it. Also, Wikipedia says it's independent of pressure, but that's assuming an ideal gas under ideal conditions, which air is not).

    Also why the super high-velocity "light gas guns" use light gas. The speed of sound in hydrogen, at atmospheric pressure, is 3.8 times higher than in air.
    Last edited: Mar 6, 2010
  15. BHP FAN

    BHP FAN Well-Known Member

    No sweat on the apology, Tank, as I kinda deserved it. I wasn't very ''High Road'', so here's me, apologizing right back at you.
  16. husker

    husker Well-Known Member

    sweet thread!!!! enjoyed this read a lot. :)
  17. oldpuppymax

    oldpuppymax Well-Known Member

    A fully loaded (110 grains) Great Plains rifle can develop just under 2300 fps.
  18. Loyalist Dave

    Loyalist Dave Well-Known Member

    the MV of a 16" naval gun is 2657 fps..., it's a black powder propelled projectile..., :what:

    well it IS! :D

  19. david58

    david58 Well-Known Member

    From my understanding, it comes down to the mass of the projectile and the relationship between the barrel length and the powder burned. I think the ideal is to burn all the powder before the ball is at the end of the bbl - thus the longer barrels tend to zip it out there a bit better.

    I have friends that try to get that long-gong shot via an extra scoop of the black stuff, and mostly it all goes to sparks and fire out the muzzle and onto the ground.

    The object is to maximize pressure, minimize projectile mass (for max muzzle velocity). But if you are hunting, you need mass to kill the critter with - which is where the trade comes in. More mass, then slower (but maintains vel with distance better than light). Seems time after time it comes around to the 40 or 45 cal as a great compromise - max velocity with enough mass for deer or antelope. But I know that my 50 will spit them out supersonic - witnessed by the crack and by the chrony...still not enough pill for an elk. There, I go to the slow, large bowling ball style of projectile, using a 60 cal for them critters. but I digress...and could be full of it to (and I am sure I'll be so informed..:D)
  20. Dave A

    Dave A Well-Known Member

    Regarding blackpowder and naval guns. Some blackpowder is used in the loading but most of the propellent is smokeless powder. The powder charge consists of multiple silk bags filled with a known weight of propellent. The "back" end of each bag had a red band indicating a layer of blackpowder. This layer was included to insure ignition of every bag in the charge. The guns were brought to level, the breech plug rotated and swung open. The projectile was placed in position on the loading tray and then rammed in to the breech ,then the powder charge was arranged in the tray and rammed slowly in to position behind the projectile. The brech plug is then swung in to position and rotated closed. Then the gun can be fired.

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