When discussing artillery ammunition, the subject of ‘hot shot’ rarely, if ever, comes up. Looking into the matter somewhat, it can be found that both land artillery and naval artillery used ‘red bullets’ though it was not a popular round to be fired because of the threat of an early detonation if the procedures for firing the round were not followed.
Regarding firing hot shot from a naval platform, a good place to begin would be Arming the Fleet: US Navy Ordnance in the Muzzle-Loading Era by Spencer Tucker, pages 93-94:
'Hot shot were also employed at sea, for wooden sailing ships were especially vulnerable to it. The shot was heated red-hot (white heat might turn it too brittle). The powder charge, contained in a strong flannel cartridge with no holes, was loaded, and then a tight, dry wad of hay 1 caliber in length was put in. This was followed by a tight clay wad or a wet hay wad with the water squeezed out. The hot shot was then loaded by means of a carrier, and the gun was fired. If it was to be fired depressed, another tight wet wad was rammed in to hold the shot in place. If two wads were used-one dry and the other damp-there was no danger of the shot causing ignition and the gun could be pointed [aimed] before it was fired.'
'The gun could also be double-shotted, that is, fired with an ordinary shot followed by a hot shot. Hot shot required a reduced powder charge, usually one-quarter to one-sixth the weight of the ball. This enabled it to penetrate the enemy hull 10 to 12 inches (if it penetrated farther, there would not be sufficient air for burning).
Excellent primary source material for firing red hot shot, or as the French called them 'red bullets', can be found in Volume II of Louis de Tousard's American Artillerist's Companion, pages 253-258.
1.The round shot would be heated on an iron grate over a 'well-kindled coal fire' and it usually took three-quarters of an hour to properly heat the shot for firing.
2.The powder charge is smaller than that for regular firing, a fourth or a fifth of the shot's weight. And the roundshot have to be carefully chosen as the heat will cause the shot to expand and then it won't fit in the bore.
3.The powder cartridge should be serge or flannel with no holes so that the powder does not 'leak' into the tube when rammed.
4.A 'good dry wad' is first used with the powder cartridge and then a damp one and then the hot shot is placed and then the entire round is rammed, then fired.
Here is an excerpt from John Elting's Swords Around a Throne in Chapter XXIV, pages 486-487 regarding 'hot shot':
'Hot shot,' the most efficient incindiary projectile, was simply a solid shot, heated in the middle of a good fire. (Coast defense forts often had special reverberatory furnaces with racks for heating large numbers of shot at one time. Captain Napoleon Bonaparte built a good many excellent ones along the Mediterranean coast in 1793.) The guns were laid on their target and carefully cleaned beforehand so no loose powder grains remained in their tubes; the powder charge was then loaded, followed by a sabot and one or more wads of woven hay, the outer one slightly dampened. That completed, the glowing hot shot was inserted in the tube and rammed down and the gun immediately fired. This could be a ticklish business, though it looked far more dangerous than it actually was; artillerymen, especially home guard types like the canoniers garde-cotes, did not like to handle 'red bullets.' In November 1810 Napoleon ordered a detailed manual printed on the use of hot shot and intensified training.'
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