The last evolution was to use a small metallic cap filled with a shock sensitive explosive compound that would ignite with a hammer strike. The source of ignition could be a burning slow match (matchlock) placed onto a touch hole, a piece of pyrite (wheellock)/flint (flintlock) striking a steel frizzen, or a shock-sensitive brass or copper percussi

All such cartridges' headspace on the case mouth (although some, such as .38 Super, at one time seated on the rim, this was changed for accuracy reasons), which prevents the round from entering too far into the chamber. Some cartridges have a rim that is significantly smaller than the case body diameter. These are known as rebated-rim designs and a