Civil War ballistics

[Tumblernotch]

Using a ballistic pendulum, the Ordnance Department compared initial velocities of the various US made small arms in inventory including the rifle-musket, the rifle M1855, an altered musket, the pistol carbine and the smoothbore M1842 musket. All were fired using the elongated ball except the smoothbore in which a round ball was used.

The rifle musket, cal. 58 was loaded with a 510 gr. elongated ball (Burton Minie) over a service charge of 60 grs. musket powder, about the equivalent of ffg. Muzzle (intial) velocity was 963 fps. Next, the M1855 rifle was fired using the exact same load. The MV was 914 fps. The variance here was caused by the shorter barrel of the rifle which was 7 inches shorter. Next was the altered musket, probably the M1816. This was a rifled musket, and converted to percussion. It used a 740 gr. Burton type Minie fired over 70 grs. of powder. Its MV was 879 fps. The pistol carbine M1855 was next and included here to show how barrel length and bullet weight has an effect on MV. The barrel was 10 inches long and the bore was .58. The bullet was quite a bit lighter at 468 grs. and fired over 40 grs. of powder. Its MV was 603 fps. The smoothbore musket was tested with a 412 gr. round ball over 110 grs. of powder, yielding a MV of 1,500 fps.

In looking at another test result from the small arms trials of 1855, I find that a smoothbore percussion musket was also shot using the same load as the altered musket. This was a 740 gr. Minie over 70 grs. of powder and the mean velocity with this load was 954 fps. This was 75 fps faster than the same caliber weapon with rifling (though there would be no accuracy). Note: all the velocities noted above are the mean velocities being the average of several shots per gun. Also, it was found that as a general rule, the first few shots fired from each gun were of a lower velocity and it was thought that the increase of succeeding shots were due to the most part, to the increase of temperatures of the barrels.

It was also found that rifling the .69 cal. barrels caused a loss in velocity of about 30 fps., and that reducing the length of the .58 cal. barrel from 40 inches (rifle-musket) to 33 inches (rifle) caused a loss of about 50 fps.

Included in this test result was a comparison to the initial velocities of the various round ball charges measured bt the same ballistic pendulum in 1844. That of the .69 cal SB musket was 1,500 fps. with 110 grs. of powder. The rifle (.54 cal.) was 1,750 fps. over 70 grs. of powder. The pistol was 947 fps. over 35 grs. of powder.

I don't have a chronograph, but I have shot both the .58 cal. rifle-musket using the service charge of 60 grs. (as well as lighter loads at targets) and the .69 cal smoothbore musket with loads of 70 to 100 grs. Firing at heavy steel gongs as far as 90 yards distance, it is easy to discern which bullet reaches the target first. Using nothing but the cartridge paper as a patch, even the "light" load of 70 grs. of ffg under a 400 gr. round ball has a shorter time of flight than a 480 to 500 gr. Minie over 60 grs. A bare ball over 85 grs. is faster than the Minie.

However, besides having lousy accuracy beyond 75 to 100 yds., the round ball loses its momentum more rapidly than the Minie. Being more efficiently designed and heavier, the Minie retains its killing power much longer and the very shape of it creates a more effective wound channel at any range. If it tumbles to a base first attitude before hitting flesh, it's even more devastating since it has become a giant hollow point.

Yes, the Minie was a great improvement, but at the muzzle out to at least 100 yds. it was a lot slower than a round ball. And still is.

 

[winfield813]

Also, any smothbore with a same or heavier weight powder charge is going to be faster as the spin/drag of the rifling slows the bullet.

I appreciate your response, but if that is so, then why do longer barrels generally equal higher velocity? If what you said is true, then a longer barrel would seem to equal less velocity and not greater. Longer barrels allow more powder to burn off and increase acceleration and rifling also serves this function in a barrel of the exact same length as a smoothbore barrel so that the rifled barrel will equal increased velocity if both barrels are of same caliber, powder charge, and bullet wieght.

 

[winfield813]

Thank you for that response. It is very helpful. If the velocity of the smoothbore is higher, what about the muzzle energy?
I shot my first Elk with a .54 caliber transfer Hawken at about 45 yards, and the bullet entered behind the shoulder (patched round ball)and turned the lungs to jelly. The stress to the tissue where the ball lodged in the far rib cage was significant. I believe, as you said, the minie ball may be even more devastating.

 

[winfield813]

Yes, the Minie was a great improvement, but at the muzzle out to at least 100 yds. it was a lot slower than a round ball. And still is.

So would it be accurate to say that the Minie ball shoots "flatter" than the round ball out of a smooth bore?
Also, at what point does the round ball out of the smooth bore lose enough force to be unlikely, if it hit, to kill a soldier or deer/bigger game?

 

[winfield813]

Another thing I am wondering about is how accurate the ballistic pendulum tests were. Shooting into a hanging block of wood and measuring its displacement seems to me to have some uncontrollable variables in it, such as how "square" the shot hit the block of wood, etc.
I have an old Black Powder Digest that gives some velocities for .577 and .58 Minie balls at + 1000 FPS (measured with a chronograph and fired with the NSSA's standard estimate of the service powder loads in the Civil War), but it had no data on smoothbores.
I have another book on firearms that gives the MV of several varieties of musket as 900 FPS, but I am not sure how that data was obtained or how accurate it is. I alos have a copy of the 1855 report on small arms tests, but the velocities given in it for smoothbores differs considerably from analysis I found in Greener's The Gun, 1834, where the author tested many of the finest British muskets of his day to judge them grossly ineffective as far as penetration and energy at any range beyond throwing distance.

 

[Tumblernotch]

I wish I could say it was, but the one day that I shot some Minies out of a smoothbore, they were so inaccurate I couldn't begin to shoot a group to see what they were capable of. I was shooting 685 gr. minies from an Ideal mold. They keyholed at 25 yards. I wasn't expecting that at 25. At 50 yds. but not that close. I can't remember how much windage I had, but they fit the bore pretty tight, so they should have obdurated enough to seal the gas pretty good in a smooth bore. It's just that with a spin to stabilize them there is no accuracy to speak of.

I didn't say much earlier about the effect of rifling and the windage of the minies used back in the day. As the report said, cutting rifling did reduce muzzle velocity. Also, the standard in the day was .005 inch windage, so for instance, a .575 bullet was generally used in a .580 inch bore. If the lead is a little too hard or not enough powder is used, the minie won't upset enough to seal the bore. Even a close fitting bullet will allow gas to pass and reduce MV. A patched ball in a rifle seals somewhat better and a close fitting patched ball in a smoothbore would be even better, seeing as how grooves provide a channel for gases to escape by.

 

[ResearchPress]

So would it be accurate to say that the Minie ball shoots "flatter" than the round ball out of a smooth bore?

The Minie was designed for the rifled barrel.

The French Nessler bullet was used in smooth-bores in the Crimean War (1856-56). It was also copied and used by the Sardinians and Russians.

The Nessler bullet is like a short smooth sided round nosed Minie, however the base cavity included a projecting cone like point.

They were reportedly superior to the spherical bullet. Russian trials noted in "The War Correspondent" (journal of the Crimean War Research Socity) reported hit percentages of 44% on company sized targets at 350 meters and 20% at 500 meters. For the spherical bullet only 3 to 4% hits at more than 300 metres and no useful accuracy or power beyond 400 metres is noted.

Contemporary testing suggests that some of the results may have been over-stated.

There is also some reference to testing of a (presumed) similar design bullet by W.B. Chace in the US. The range when the Chace bullet was fired from a musket and when compared to a round-ball cartridge from the same musket was increased by a third. See Joe Bilby's "Civil War Firearms".

The Nessler bullet was not used in Britain and despite some testing in the US was not adopted.

David

 

[pargent]

Just athought when a .58 .62 .69 projectile hits flesh &bone expansion is not realy needed, not like on a modern projectile. :v

 

[Zonie]

I agree.
When a bullet or ball starts off larger than a modern bullet can expand to one can expect to see a LOT of damage to whatever it hits.

 

[winfield813]

Thanks for the responses so far. They have been very helpful.
Here is a link to some ballistic wound comparisons between the two and apparently, though the rifle musket has a lower initial velocity and the wounds between it and a smoothbore fired at close range are very similar in soft tissue, but when it hits bone, the Minie ball is more devastating.
http://www.bordeninstitute.army.mil/published_volumes/conventional_warfare/ch03.pdf

 

[Norinco]

Ballistic pendulums are incredibly reliable. It works on some very basic principles of physics. It's not hard to ensure that each shot hits square to the pendulum each time. Also, the multiple trials helps to average out any error that may occur.

 

[winfield813]

Good to know. Thank you.

 

[Tumblernotch]

Another thing I am wondering about is how accurate the ballistic pendulum tests were. Shooting into a hanging block of wood and measuring its displacement seems to me to have some uncontrollable variables in it, such as how "square" the shot hit the block of wood, etc.
I have an old Black Powder Digest that gives some velocities for .577 and .58 Minie balls at + 1000 FPS (measured with a chronograph and fired with the NSSA's standard estimate of the service powder loads in the Civil War), but it had no data on smoothbores.
I have another book on firearms that gives the MV of several varieties of musket as 900 FPS, but I am not sure how that data was obtained or how accurate it is. I alos have a copy of the 1855 report on small arms tests, but the velocities given in it for smoothbores differs considerably from analysis I found in Greener's The Gun, 1834, where the author tested many of the finest British muskets of his day to judge them grossly ineffective as far as penetration and energy at any range beyond throwing distance.

Actually, the ballistic pendulum used at the time of the Civil War was a battery powered "electro-ballistic pendulum". It was mostly used in obtaining velocities for cannon, but was also used for small arms. It used copper wires rather than wooden blocks for the targets. Two wire targets were set up at varying distances from the muzzle. The pendulums were actually part of the measuring device and they marked a piece of paper. The set-up of the targets is similiar to that of a chronograph only farther apart. There is an explanation of this machine and a drawing in the 1862 US Army Ordnance Manual.