An interesting test was recently conducted in Austria with original firearms from museum collections, manufactured between 1571 and 1700. A target the shape and height of an average human figure was shot at from 30 m/100 ft and 100 m/330 ft. About 20 smooth-bore arquebuses, matchlock and wheel-lock muskets were tested, and the results showed that the probability of a hit at 100 m/330 ft from a weapon fastened to the test table was 40 to 50 per cent; at 30 m/100 ft, the ball could pierce armour 3-4 mm thick, and at 100 m/330 ft armour 1-2 mm thick (for comparison, a modern Belgian FN assault rifle can pierce 12 mm of armour at 100 m/330 ft). The only real difference among the weapons was that the later models were lighter and had a greater rate of fire. Three pistols were also tested, one made in 1620 and the other two in 1700. The probability of scoring a hit from them at 30 m/100 ft (also fastened to the test table) was much higher: 85 to 95 per cent. All three could pierce 2 mm of armour.

The firepower of infantry and cavalry forced armoured riders from the battlefields towards the end of the seventeenth century. The rate of fire was also increased, while the cost of firearms manufacture went steadily down. For a while, armoured cavalry tried to fight back with the use of musketproof breastplates and pistol-proof backplates; together, these weighed over 15 kg/33 lb, and the protection provided did not justify its high price or inconvenience. At the beginning of the eighteenth century, France, Bavaria, Austria, Saxony, Brandenburg, Denmark and Holland equipped their cuirassiers with breastplates and backplates which were similar, and with hats under which steel skull-caps were worn. In 1698, Britain officially abolished the use of armour in regiments of horse, but reintroduced a breastplate worn under the coat in 1707, at the time of the War of the Austrian Succession. Armour was not seen again until the coronation of George IV (1821), and then only for the Household Cavalry.

The weight of a breastplate was about 5 kg/11 lb, and it was about 2-3 mm thick. It was primarily meant to protect the rider from cutting and thrusting weapons, although it was effective against firearms too, up to a certain distance. Until the mid-eighteenth century, armour was made up by the forging of hot metal plates on specially shaped casts. The first series of breastplates made by cold pressing was manufactured in Prussia in 1755. This new technology made possible the production of larger batches of armour of standard quality.