As I understand the self primers, the Sharps used a Lawrence automatic tape primer system, revised many times from individual cap feed in the model 1849 Slant Breech Sharps rifle. the originals might have been Sharps patents, but the Lawrence being adapted later on, which used a tape-type primer strip similar to the Maynard tape primer. These changes occurred over a fairly short period of time. The cap-lock military guns of the 50's etc. used the Maynard tape priming device.