Many times, I’ve been asked about musket balls and how they fit in the bore of a gun during the American Revolution. Unlike today where the bullet fits tightly into a rifled bore, this was not the case for smoothbore arms in the 17th, 18th, or the 19th century. In order to understand the ball vs. bore in a smoothbore musket for fowling piece, we need to discuss the bore of the guns also.
British land pattern muskets used during the Revolution are generically stated to be .75-inch in diameter. A study I have done of 80 original British muskets in very good condition shows that the bores have a range of .75-inch to .82-inch with an average of .78-inch. Gun barrels during the period were made from flat stock, which was hammered around a mandril and welded, so being thus made each one slightly different.
British musket balls are listed as 14 balls to the pound for service, which according to a chart in the manuals shows them as .693-inch. However, a study of 184 original British musket balls found in an archaeological context shows that like the bores of the guns, the balls are not that exact in size. They range from .66-inch to .72-inch with an average of .68-inch.
Given that Provincial arms were so varied at the outbreak of the Revolution, there was no ball size that could be specified. They were using everything from small bore fowling pieces, older French arms, guns assembled from a variety of parts, and some older British arms. Based upon extant arms with a provenance, documents, and the archaeological record, the most commonly used gun was the fowling piece. The bores of most of the fowling pieces are generally smaller and average in the .62-inch range. The ball that would be fired out of a gun with a .62-inch bore would be in the .56-inch range. The reason for the smaller ball size is to adjust for powder fowling, as well as a paper cartridge. This is called windage.
Not all of the minute or militia men on April 19, 1775, were using paper cartridges. A newspaper article published on March 11, 1775, states: “I Have great reason to think from the observations I have made, that there is not a proper regard paid to the importance of having Cartridges properly made with a Ball in each. I would therefore strongly recommend it to my countrymen immediately to be provided each man (able to bear arms) with at least twenty well made Cartridges.” It goes on to state that a soldier can fire four shots with a paper cartridge and is faster than loading with a powder horn and loose ball. A few weeks after the war broke out, a memorandum on arms states: “That each Soldier have such Cartridges that will slide down without Drawing the Rammer.” That’s a pretty loose fit!
