Table What size cannon balls were used in the Civil War?

Civil War Cannon-Balls and Cannon-Shells came in a large variety of sizes! Some were as small as a modern baseball, and some were much larger than a modern basketball!

1580489540137.png

Confederate torpedoes, shot, and shells in front of the arsenal, Charleston, SC, 1865.
Photo by Selmar Rush Seibert. National Archives

First it's important to note that smoothbore guns typically fired round balls, and rifled guns most frequently fired elongated shot, similar to the shape of bullets you would see in use today. Rifled shot was typically 2 to 4 times heavier than the equivalent Round Ball shot by bore size.

HOW BIG WERE CIVIL WAR "CANNON BALLS"?

To explain, we will use the size of the cannon's bore, which would be just slightly larger than the diameter of the projectile or ball. The notation for this was known as the cannons caliber, and it was measured in inches. It would also similar to the size of the hole that would be punched in a target by the projectile or ball.

Here are some Typical Examples, with a few modern equivalents (in green), and Famous Civil War Cannons (in blue) for comparison:

Caliber or
Size of Shot
Caliber in
Metric
Round Ball SizeCommon Civil War Era Cannons of this Bore Size *
2.46 inches​
62.4 mm​
2-pdr.​
(an uncommon size during the ACW)
2.6 inches​
66.0 mm​
-​
6-pdr. Wiard
2.91 inches​
73.9 mm​
3-pdr.​
10-pdr. Parrott (Baseball 2.875")
3.0 inches
76.2 mm​
-​
3-inch Parrott, 3-inch Ordnance Rifle, 12-pdr. Whitworth
3.2 inches​
81.3 mm​
4-pdr.​
(an uncommon size during the ACW, much more common post-war, late 1800's)
3.4 inches​
86.4 mm​
-​
12-pdr. Rifled Boat Howitzer
3.5 inches​
88.9 mm​
-​
12-pdr. Blakely Rifle
3.67 inches
93.2 mm​
6-pdr.​
6-pdr. Gun, 20-pdr. Parrott, 12-pdr. Wiard (Croquet 3.625")
3.8 inches​
96.5 mm​
-​
14-pdr. James Rifle (Softball 3.82")
4.2 inches​
106.7 mm​
9-pdr.​
(Bocce ball 4.2")
4.5-inches​
114.3 mm​
-​
30-pdr. Parrott, Siege Rifle (Long Tom)
4.62 inches
117.3 mm​
12-pdr.​
12-pdr. Napoleon, 12-pdr. Howitzer, 24-pdr. James Rifle (Duckpin Bowling Ball 5")
5.29 inches​
134.4 mm​
18-pdr.​
M1845 18-pdr. Iron Siege Gun
5.82 inches​
147.8 mm​
24-pdr.​
24-pdr. Howitzer
6.41 inches​
162.8 mm​
32-pdr.​
100-pdr. Parrott, 32-pdr. Howitzer U.S.
7.02 inches​
178.3 mm​
42-pdr.​
42-pdr. Howitzer
7.50 inches​
190.5 mm​
-​
7.5" Blakely Rifles (Widow Blakely)
8.0 inches​
203.2 mm​
8-inch​
VIII Dahlgren, 8" Rodman, 150/200-pdr. Parrott (Swamp Angel) (Volleyball 8.39")
9.0 inches​
228.6 mm​
9-inch​
IX Dahlgren (Basketball 9.4")
10.0 inches​
254.0 mm​
10-inch​
X Dahlgren, 10" Rodman, 300-pdr. Parrott
11.0 inches​
279.4 mm​
11-inch​
XI Dahlgren (Monitor's Guns)
13.0-inches​
330.2 mm​
13-inch​
XIII Dahlgren, 13" Rodman, 13" Seacoast Mortar (The Dictator) (Lg. Medicine Ball 13.7")
15.0 inches​
381.0 mm​
15-inch​
XV Dahlgren, 15" Rodman
*Equivalent Modern Sports Ball Equivalent Size Provided for Reference in Green

RULES FOR NAMING SMOOTHBORE CANNONS


The size-name of smoothbore cannons and their projectiles (for example: 6-pounder or a 12-pounder) was signified by the size of the bore diameter of the cannon's barrel, or caliber. The caliber size would then be matched up to the approximate weight of the solid iron cannonball shot.

You can think of it like this: a cannon like a Napoleon with a bore diameter of 4.62 inches would shoot a solid iron ball that would weigh about 12 pounds, but a cannon with a bore diameter of 7.02 inches would shoot a ball that weighed as much as 42 pounds.

So, for smoothbore guns, the size of the cannon was referred to in terms of the average weight of the solid ball shot they could fire. A cannon that shot a 6-pound ball was called a 6-pounder, and might be abbreviated as: "6-pdr."

A smoothbore cannon that shot a 24-pound ball was called notated as: 24-pdr.

This naming practice had been in place for over a century in the United States, including for guns used during the American Revolution.

One new change in the modern era of smoothbore guns was that any smoothbore gun above 7-inches in caliber is designated by it's size in inches, rather than weight. So the Rodman Cannon, with the 15-inch bore, was a 15-inch Rodman. The Navy used a similar system, except it used roman numerals for the inch measurements. So a Dahlgren Gun, with a 15-inch bore, was a XV-inch Dahlgren!

All these simple rules had to be re-written with the invention of "Rifling", as militaries learned of the advantages of distance and accuracy in the new system, the new guns just couldn't be classified with this system.

1580487465112.png

"View of rows of stacked cannon balls." National Archives Photo taken by Mathew Brady between 1861-1865.
Note: On the Left side, the first set of stacks in the rear includes Whitworth Shells, probably of the 12-pdr. variety.

CONFUSION IN RULES FOR NAMING RIFLE CANNONS

Rifled guns couldn't easily follow the rules smoothbores had used for over a hundred years, not exactly. It seems that depending on the manufacturer, some rifled guns were designated with a classic smoothbore weight like name, and others by the caliber in inches. Rifled guns were such a new technology for the military, the armies had yet to make a standardized naming system for them.

All of this confusion comes from the elongated shell making the projectile two to four times heavier then round balls in the same caliber gun. Also, the weight could vary depending on the length of the projectile, and some rifled guns did have multiple length shells available for use. That didn't stop manufacturers from using the popular "pounder" designation though, even when it didn't completely make sense.

Take for instance, the 2.9 inch, 10-pdr. Parrott Rifle, this would be a 3-pdr. gun if it was shooting round balls. This common Civil War cannon was redesigned in 1863 as a 3-inch rifle to be more compatible with other guns also in the field, but they still considered the gun a 10-pounder Rifle! At least most of it's ammunition was still between 9¾ lbs. and 10½ lbs.

On the other hand, you have the Army 200-pdr. Parrott Rifle. How heavy would you expect it's typical projectile to be? Well, typically this gun fired 150 lb. shells from it's 8-inch bore! An early design shell did in fact weigh 200 lbs. but a lighter design was found to function more favorably. However, the confusion doesn't end there because, this exact same gun was also called the 150-pdr. Parrott by the Navy, and that just to adds to everyone's confusion.

Why no-one thought to just call this gun an 8-inch Parrott Rifle for both the Army and Navy, and be done with it, is amazing!

Mismatches like this weren't uncommon among the many varied Civil War era rifle cannons, and some of the imported cannons for the Confederacy were unique and didn't always classify easily with other guns.

As an example, the British Whitworth Rifle fires a 12 pound projectile, so it's called a 12 pounder Whitworth Rifle. That's the easy part. What is it's bore size? You might see it listed as a 3-inch gun, and you might see it listed as a 2.75 inch gun. Why the discrepancy? Well, the bore, and the projectiles aren't round per say, they are hexagonal, and when you measure them you can do it two ways. You can measure the flats, that's the smaller "bore diameter" of 2.75 inches, or you can measure from opposite corners, and that's the larger measurement of 2.99" or nearly 3-inches.

Even after years of study, there is always something new to learn about Civil War Artillery!
 
Last edited:

Lubliner

Captain
Forum Host
Joined
Nov 27, 2018
Location
Chattanooga, Tennessee
They say its not the size of the cannon ball that matters.
...nor is it the length of the gun. It is the bang for the buck! (sorry)

I did have a real question on:

"You can think of it like this: a cannon like a Napoleon with a bore diameter of 4.62 inches would shoot a solid iron ball that would weigh about 12 pounds, but a cannon with a bore diameter of 7.02 inches would shoot a ball that weighed as much as 42 pounds." (above).

Using this as an example, how were the solid shot compared with exploding cannonballs that had hollow cavities filled with powder, as far as weight differences, and regarding diameters? There seemed to be a variety of shells made that could be fired by the same weapon, and confusing it further, the the larger bore could be fitted with a smaller round if necessary, or am I mistaken? I seem to recall any angle of declination below horizon were impossible without the correct packing size.
Thanks,
Lubliner.
 
Joined
Aug 1, 2018
Location
Nashville, TN
Civil War Cannon-Balls and Cannon-Shells came in a large variety of sizes! Some were as small as a modern baseball, and some were much larger than a modern basketball!

View attachment 344488
Confederate torpedoes, shot, and shells in front of the arsenal, Charleston, SC, 1865.
Photo by Selmar Rush Seibert. National Archives

First it's important to note that smoothbore guns typically fired round balls, and rifled guns most frequently fired elongated shot, similar to the shape of bullets you would see in use today. Rifled shot was typically 2 to 4 times heavier than the equivalent Round Ball shot by bore size.

HOW BIG WERE CIVIL WAR "CANNON BALLS"?

To explain, we will use the size of the cannon's bore, which would be just slightly larger than the diameter of the projectile or ball. The notation for this was known as the cannons caliber, and it was measured in inches. It would also similar to the size of the hole that would be punched in a target by the projectile or ball.

Here are some Typical Examples, with a few modern equivalents (in green), and Famous Civil War Cannons (in blue) for comparison:

Caliber or
Size of Shot
Caliber in
Metric
Round Ball SizeCommon Civil War Era Cannons of this Bore Size *
2.46 inches​
62.4 mm​
2-pdr.​
(an uncommon size during the ACW)
2.6 inches​
66.0 mm​
-​
6-pdr. Wiard
2.91 inches​
73.9 mm​
3-pdr.​
10-pdr. Parrott (Baseball 2.875")
3.0 inches
76.2 mm​
-​
3-inch Parrott, 3-inch Ordnance Rifle, 12-pdr. Whitworth
3.2 inches​
81.3 mm​
4-pdr.​
(an uncommon size during the ACW, much more common post-war, late 1800's)
3.4 inches​
86.4 mm​
-​
12-pdr. Rifled Boat Howitzer
3.5 inches​
88.9 mm​
-​
12-pdr. Blakely Rifle
3.67 inches
93.2 mm​
6-pdr.​
6-pdr. Gun, 20-pdr. Parrott, 12-pdr. Wiard (Croquet 3.625")
3.8 inches​
96.5 mm​
-​
14-pdr. James Rifle (Softball 3.82")
4.2 inches​
106.7 mm​
9-pdr.​
(Bocce ball 4.2")
4.5-inches​
114.3 mm​
-​
30-pdr. Parrott, Siege Rifle (Long Tom)
4.62 inches
117.3 mm​
12-pdr.​
12-pdr. Napoleon, 12-pdr. Howitzer, 24-pdr. James Rifle (Duckpin Bowling Ball 5")
5.29 inches​
134.4 mm​
18-pdr.​
M1845 18-pdr. Iron Siege Gun
5.82 inches​
147.8 mm​
24-pdr.​
24-pdr. Howitzer
6.41 inches​
162.8 mm​
32-pdr.​
100-pdr. Parrott, 32-pdr. Howitzer U.S.
7.02 inches​
178.3 mm​
42-pdr.​
42-pdr. Howitzer
7.50 inches​
190.5 mm​
-​
7.5" Blakely Rifles (Widow Blakely)
8.0 inches​
203.2 mm​
8-inch​
VIII Dahlgren, 8" Rodman, 150/200-pdr. Parrott (Swamp Angel) (Volleyball 8.39")
9.0 inches​
228.6 mm​
9-inch​
IX Dahlgren (Basketball 9.4")
10.0 inches​
254.0 mm​
10-inch​
X Dahlgren, 10" Rodman, 300-pdr. Parrott
11.0 inches​
279.4 mm​
11-inch​
XI Dahlgren (Monitor's Guns)
13.0-inches​
330.2 mm​
13-inch​
XIII Dahlgren, 13" Rodman, 13" Seacoast Mortar (The Dictator) (Lg. Medicine Ball 13.7")
15.0 inches​
381.0 mm​
15-inch​
XV Dahlgren, 15" Rodman
*Equivalent Modern Sports Ball Equivalent Size Provided for Reference in Green

RULES FOR NAMING SMOOTHBORE CANNONS


The size-name of smoothbore cannons and their projectiles (for example: 6-pounder or a 12-pounder) was signified by the size of the bore diameter of the cannon's barrel, or caliber. The caliber size would then be matched up to the approximate weight of the solid iron cannonball shot.

You can think of it like this: a cannon like a Napoleon with a bore diameter of 4.62 inches would shoot a solid iron ball that would weigh about 12 pounds, but a cannon with a bore diameter of 7.02 inches would shoot a ball that weighed as much as 42 pounds.

So, for smoothbore guns, the size of the cannon was referred to in terms of the average weight of the solid ball shot they could fire. A cannon that shot a 6-pound ball was called a 6-pounder, and might be abbreviated as: "6-pdr."

A smoothbore cannon that shot a 24-pound ball was called notated as: 24-pdr.

This naming practice had been in place for over a century in the United States, including for guns used during the American Revolution.

One new change in the modern era of smoothbore guns was that any smoothbore gun above 7-inches in caliber is designated by it's size in inches, rather than weight. So the Rodman Cannon, with the 15-inch bore, was a 15-inch Rodman. The Navy used a similar system, except it used roman numerals for the inch measurements. So a Dahlgren Gun, with a 15-inch bore, was a XV-inch Dahlgren!

All these simple rules had to be re-written with the invention of "Rifling", as militaries learned of the advantages of distance and accuracy in the new system, the new guns just couldn't be classified with this system.

View attachment 344467
"View of rows of stacked cannon balls." National Archives Photo taken by Mathew Brady between 1861-1865.
Note: On the Left side, the first set of stacks in the rear includes Whitworth Shells, probably of the 12-pdr. variety.

CONFUSION IN RULES FOR NAMING RIFLE CANNONS

Rifled guns couldn't easily follow the rules smoothbores had used for over a hundred years, not exactly. It seems that depending on the manufacturer, some rifled guns were designated with a classic smoothbore weight like name, and others by the caliber in inches. Rifled guns were such a new technology for the military, the armies had yet to make a standardized naming system for them.

All of this confusion comes from the elongated shell making the projectile two to four times heavier then round balls in the same caliber gun. Also, the weight could vary depending on the length of the projectile, and some rifled guns did have multiple length shells available for use. That didn't stop manufacturers from using the popular "pounder" designation though, even when it didn't completely make sense.

Take for instance, the 2.9 inch, 10-pdr. Parrott Rifle, this would be a 3-pdr. gun if it was shooting round balls. This common Civil War cannon was redesigned in 1863 as a 3-inch rifle to be more compatible with other guns also in the field, but they still considered the gun a 10-pounder Rifle! At least most of it's ammunition was still between 9¾ lbs. and 10½ lbs.

On the other hand, you have the Army 200-pdr. Parrott Rifle. How heavy would you expect it's typical projectile to be? Well, typically this gun fired 150 lb. shells from it's 8-inch bore! An early design shell did in fact weigh 200 lbs. but a lighter design was found to function more favorably. However, the confusion doesn't end there because, this exact same gun was also called the 150-pdr. Parrott by the Navy, and that just to adds to everyone's confusion.

Why no-one thought to just call this gun an 8-inch Parrott Rifle for both the Army and Navy, and be done with it, is amazing!

Mismatches like this weren't uncommon among the many varied Civil War era rifle cannons, and some of the imported cannons for the Confederacy were unique and didn't always classify easily with other guns.

As an example, the British Whitworth Rifle fires a 12 pound projectile, so it's called a 12 pounder Whitworth Rifle. That's the easy part. What is it's bore size? You might see it listed as a 3-inch gun, and you might see it listed as a 2.75 inch gun. Why the discrepancy? Well, the bore, and the projectiles aren't round per say, they are hexagonal, and when you measure them you can do it two ways. You can measure the flats, that's the smaller "bore diameter" of 2.75 inches, or you can measure from opposite corners, and that's the larger measurement of 2.99" or nearly 3-inches.

Even after years of study, there is always something new to learn about Civil War Artillery!
Thank you. This is very helpful.
 
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