Trapper's   of   Starved   Rock
St. Charles, Missouri
MUZZLE VELOCITY
                                                             Trappers of Starved Rock Muzzle Loading Forum

Over the years, about 54, that I have enjoyed this sport, recreational hobby, obsessive passion, or whatever it is, of muzzle loading, I have
gathered quite a bit of information, and I would like to pass some of it on to my fellow Trappers of Starved Rock- for whatever use it is to
you. Some of this info is hard data and experimental results and some is my personal experience and opinion and some is folklore or myth
that I hold to be of value. Those who know me know I am a traditionalist as far as our sport goes. I love studying the history of our
forefathers and following in their footsteps. If it was good enough for Hawk Eye, Dan’l Boone and Jedediah Smith, it is good enough for me;
e.g. black powder and round balls.

I hope you, my fellow Trappers, will correct my ramblings and add you own advice to these pages so we end up with a document of value for
our future new members.

Muzzle Velocity
The first subject I would like to address is muzzle velocity- the speed of the projectile as it leaves the barrel. I was recently looking through
the mess of muzzle loading “stuff” in my basement, and I came upon these graphs that I drew, probably 20 or 30 years ago. That’s when I
decided to make them and other info available to you. These are plots of data from either the old Lyman Muzzle loading manual or an old
Thompson Center handbook. TC was one of the first companies (along with Connecticut Valley Arms –CVA) to make quality mass produced
muzzle loaders available. Lyman is the company that makes bullet molds- the best bullet molds in my opinion. I haven’t seen these data
published recently so here they are.

Muzzle velocity is determined by many factors: caliber of your firearm, size and weight of the projectile, amount of black powder, granulation
of the powder FFg, FFFg, etc,  thickness of your patch, patch lube and barrel length.  In short, within limits, the more powder, the lighter the
ball, the tighter the fit in the barrel the higher the muzzle velocity.

Black Powder comes in various grain sizes designated Fg, FFg, FFFg and FFFFg. The more F’s the finer, smaller the grain size and the
faster the powder will burn and the higher pressure it generates in your barrel.  In a 54 caliber rifle, sixty grains of FFFg creates the same
pressure at the breech as one hundred grains of FFg. Sixty nine grains of FFFg provides the same muzzle velocity as one hundred grains
of FFg –Lyman data.  These are linear relationships, so you can use these ratios to determine how much FFFg it takes to replace your FFg
load. Since both granulations cost the same per pound, you can see why a Scotsman might use FFFg.

Fg is recommended for shotguns and cannon, FFg for rifles over 50 caliber, FFFg for rifles less than 50 caliber and pistols. FFFFG is for
priming your flintlock. FFFg and FFg will work as priming powder, but it can be a little slower to ignite. They did not have superfine FFFFG,
or at least it wasn’t common for the “common folk” in days of the American Revolution, so if you want to be strictly period correct…….

I use FFG in my 54, 58 caliber rifles and my 62 caliber fusil - also called a fowler or smoothbore. A charge of XX grains is actually a weight
measurement. There are 7000 grains in a pound. But we have calibrated powder measures that allow us to use a volume measure equal to
XX grains for convenience. Some of our friends, one John R. Adams comes to mind, use FFFG in their larger caliber firearms even their 62
caliber smoothbores. They say it shoots cleaner. BUT remember the higher pressures you are creating in the firearm! You should NEVER
replace a FFg load of powder with the same size load of FFFg.

When, in days gone by, I shot my percussion 54 caliber Hawken rifle at long range (200 yards) silhouettes at Friendship and/or went Elk
hunting, I used 120 grains of FFg. (Tip#1 That charge would burn-up the patch and harm accuracy, so I loaded a “sacrificial patch or 80
grains of Cream of Wheat” on top of the powder charge before I loaded the patched ball.) If I had used 120 grains of FFFg the pressure
would have been equivalent to 200 grains of 2F-clearly too high!

The muzzle velocity created as a function of the black powder charge size is shown in Figure 1. These data are experimental results
published by Thompson Center. These data were generated with TC firearms and patching material. The 45, 50 and 54 caliber data use
FFg DuPont, now Goex, black powder. The 36 caliber Seneca rifle used FFFg.
The two curves labeled 45 caliber represent two rifles, the Seneca, a smaller, shorter barrel rifle and the Hawken which is heavier and has a
longer barrel. The longer barrel produces slightly higher velocities ( about 20 ft. per second ) because all the powder is burned inside the
barrel and/or the pressure has longer to act on the projectile. I’m not sure which is the greater influence, but it isn’t a major factor. Also you
can see that in all cases the larger charges are less efficient at creating velocity.

Here are the ball sizes and weights used to create these data.
                             Caliber      Ball Diameter      Ball weight – Grains
                                 36                  0.35”                     65
                                 45                  0.440                    127
                                 50                  0.490                    175
                                 54                  0.530                    230

Obviously the larger, heavier ball requires more powder to achieve the same velocity as the small ball. If you want high velocity get a 36
caliber pea shooter.

OK, why do we want high velocity? There are two reasons. First, there is gravity. As soon as the ball leaves the barrel gravity starts pulling it
down. The acceleration of gravity (g) is 32.2 feet per second squared. The distance (d) an object falls over time (t) is    d= 0.5 g  t t.
So If you shoot at an object 100 yards away and the AVERAGE velocity of the ball from the time it leaves the barrel till it reaches the target
is 1000 ft per second, the ball falls 1.449 feet before it hits the target. Therefore you must aim your rifle 1.449 feet above the target to hit it
exactly. If the Average velocity is increased to 1500 feet per second the ball drop is only 0.644 feet. The velocity increased by a factor of
1.5, but the drop decreased by a factor of 2.25. Notice that this is AVERAGE velocity and Figure 1 gives us Velocity at the muzzle.
Unfortunately round balls have high aerodynamic drag and slow down more quickly than a streamlined bullet.

The aerodynamic drag force F that slows the projectile is proportional to the current velocity V, the presented area of the projectile A-
divided by the weight W, and the drag coefficient of the projectile shape CD. The drag coefficient varies with the current velocity, which
makes it difficult to calculate projectile velocity along the trajectory. I’m looking for a free ballistics program on the Internet, but I haven’t
found one. I have a degree in aeronautical engineering, but I’m sorry to say I forgot how to integrate all that. Elongated bullets don’t slow
down and therefore drop as much as a round ball because bullets have a lower CD and they have a lower presented area A for the same
weight W.

The second reason you want high velocity and a larger ball is to deliver more energy to the target-whether the target is a steel silhouette or
a deer. Figure 2 presents the energy measured in foot pounds at the muzzle as a function of powder charge and ball size. The 50 and 54
caliber balls have a very significant advantage over the 36 and 45 calibers. Again this is energy at the muzzle and not at the target.

Muzzle velocity also depends on the tightness of the ball and patch in the barrel. If the fit is loose, gas will escape around the ball and lessen
the force accelerating the ball. The British Brown Bess musket used in the days of the American Revolution was about 75 caliber and they
used a 69 caliber ball without a patch. The idea was not to fire accurately at long range but to fire quickly, create a massed fire at short
range- probably about 60 yards. The British infantryman could load and fire 3 times a minute. The undersized ball loaded quickly- until the
barrel became choked with fowling. But they didn’t usually get in long firefights. They usually fired a volley, advanced several yards,
reloaded, fired another volley and then charged with their bayonets.

With a rifle gun, we also want a tight fit so the rifling creates a spin on the ball. The spinning ball is more stable and flies straighter – like
throwing a football. That’s why rifle guns are more accurate than smoothbores beyond say 50 yards or so.

With a muzzleloader you need to know where your ball impacts at different ranges- 20 yards, 50 yards, 100 yards etc. so you can change
your point of aim to hit the target.