The Accuracy Of Black Powder Muskets - willegal.net

1 The Accuracy Of BlackPowder MusketsByMike Willegal Copyright 1999, Michael J. Willegal, Tewksbury, MAIntroductionThis article covers an attempt of mine to analyze some data I have come across regarding the BrownBess VelocityHow the amount of Powder loaded into the weapon affects the muzzle velocity is shown by thefollowing chart. This test was conducted using a greased and patched .715" ball weighing 545 modern FFg power1. I would think that in battle, a hastily loaded weapon would not performas well and certainly not as consistently. The actual standard load of a Brown Bess cartridge was 6to 8 drams2. A dram equals about grains, so the actual load for the period would be 165 to 220grains minus the amount used to prime the pan. However modern Black powders have much betterquality as far as consistency and Velocity (FPS)20406080100120140 Grains of powderQuality of PowderSome other tests were conducted with a standard Civil War Minnie ball using two different grades ofmodern commercially available Black power4.

2 The interesting thing is the change in muzzle velocitybased upon the power used. That this could have a some effect on Accuracy at longer ranges as willbe seen in the next section. If modern powders could be this different, it hard to imagine what thingswere like during the Napoleonic wars, especially on an extended DropThe following chart shows the expected drop from a brown bess musket at various ranges andmuzzle velocities6. Remember that this is theoretical data, not what one would see on every of many sorts would make it difficult to have repeatable results at longer ranges, butfor that sake of this discussion, lets go with the only data for muzzle velocity of 1000 fps, 900 fps, 800 fps and 700 fps. inches of drop050100150200250300 The drop of a ball fired from a brown bess is considerable, from 250 to 450 inches at 300 yards,depending upon muzzle velocity.

3 Note that a 5 8" high man is only 68" high. At 300 yards a ballfired at 1000 fps will drop a total of more than 20 feet. In other words to hit a target at 300 yards themusket barrel must be pointed directly at a spot 20 feet inches above the target!! However at 75yards the worst case drop is only 22 inches, less than two feet!Notice that the difference between the drop of a high velocity 1000fps and low velocity ball 700fpsis almost as much as the total drop of the high velocity ball. Drop is important because it affectshow much you must raise the front of the barrel to be able to hit a target at longer ranges. It will alsoaffect the difference between the minimum and maximum elevations at which a brown bess must beaimed to hit a target at a given range.

4 A ball that is fired out to a range that has a lot of drop has asmaller chance to hit a target. If the target is closer than expected the ball may fly over it. If thetarget is farther than expected the ball will land short. However at close range the chances are theball will strike close to the target, because the musket is aimed fairly close to level. A ball fired athigher velocity will cover more area between the time it reaches a height say 5 8" that could hit aman and before it hits the and the "Danger Zone"Sights on the brown bess consisted of a piece of metal mounted at the front of barrel. Some say thatthe sight was really just a mounting point for the danger zone is a term I have borrowed from naval warfare. When firing a weapon at a distancethe ball will have a chance of hitting a target at a longer range than expected.

5 That is the target is nota point, but a certain height. When the target is further than expected, the ball may still hit if it doesnot strike the ground before it reaches the target. Conversely, if the target is closer than expected,the target may still be hit, if the ball falls to the maximum height of the target before it passes be-yond the I do not know at what ranges the various weapons tended to be sighted in for (I am using thisterm loosely, given the primitive sights of weapons involved). I have run some calculations on whatthe danger zone would be if the weapons were sighted in at 75, 150 and 250 yards. This should giveyou some idea of how much error would be allowed before a miss are several assumptions taking place here. The musket is fired from a height of 60 inches The target is 68 inches high.

6 The ball has a muzzle velocity of 900 fps and another batch of data was calculated with a muzzlevelocity of 700 fps. A ball with a slower muzzle velocity would have a smaller danger zone and aball with a faster muzzle velocity would have a larger danger danger zone is expressed in terms of the amount of deviation in degrees that the musket barrelmight take from true (aimed 8 inches below the top of the target) and still allow the ball to hit thetarget without flying over or hitting the ground first. High is the amount of degrees higher than thetarget that the weapon can be aimed and still achieve a hit. Low is the amount of degrees lower thanthe target that the weapon can be aimed and still achieve a hit. The best results will normally beachieved when the high and low angles are centered on the target.

7 That way a slight deviation ineither direction will still achieve a hit. Note that the total degrees of freedom does not change withthe sighting range only where the shot will be things affect Accuracy as the range is ) There is less degrees of freedom because the target occupies a smaller angle in the fieldof ) The danger zone is smaller making the degrees of freedom ) Unless the weapon is sighted in at a longer range or is pointed high, the balls will tend tofall zone if sighted in at 75 (900 fps)Danger zone if sighted in at 75 (700 fps)range elev. high low ave total range elev. high low ave total75 75 (low) (low) 150 250 zone if sighted in at 150 (900fps)Danger zone if sighted in at 150 (700fps)range elev.

8 High low ave total range elev. high low ave total75 75 (low) 75 (low) 150 250 zone if sighted in at 250 (900 fps)Danger zone if sighted in at 250 (700fps)range elev. high low ave total range elev. high low ave total75 75 (low) 75 (low) .92 150 .61 250 closer to zero the average is, the greater the effect a given volley will have. This is becauseshots will be centered around this point.

9 If the point is not centered on the target the shots will bemore likely to miss. Given all these assumptions, a Brown Bess fired at 900 fps and sighted in at150 yards, and aimed low at 75 yards will be the best performer with a total average of .90. Thesecond best is the same setup only at 700 fps with a total of The worst total is sighted inat 250 yards. This tends to show that aim point is more significant than muzzle velocity in Accuracy ,which would seem to make sense. Remember that this is only a small sample of an infinite numberof of muzzle velocityThe difference between 700 and 900 fps is very small at 75 yards and increases slightly at 150 at 250 yards does it become really significant. The muzzle velocities listed here are lower thanthose reported for Black Powder era flintlock Muskets .

10 This should not greatly affect our presump-tions, because muzzle velocity is shown to be a small factor in HISTORIC MUZZLE .69 Cal. flintlock musket110 grains powder412 gr ball1500 .69 Cal. musket120 grains powder1426 fps8 Adjustment for close range firing at feetThe above tables list an alternate danger zone, labeled low. This the effect the firing at the targetsfeet at close range will have. This can be calculated to have an effect of slightly less than 1 degree at75 yards range. It is assumed that firing at the targets feet did not occur at much greater ranges thanthis. In fact at 150 yards, firing at the feet of the target only affects the aim point by .5 degrees. It iseasily discernible in the data presented here that firing at the target's feet has a positive effect onaccuracy at close range no matter how the weapon is sighted.