I have a few specific questions, but I want to establish terminology first. When I say "firearm(s)", "rifle(s)", and "pistol(s)" I am referring ONLY to hand-held matchlock, wheellock, and flint-lock devices with triggers from before the year 1800. I am NOT referring to cannons, "hook guns" like the arquebus, or modern guns like the AK-47.

1. Were rifles more commonly firing balls at subsonic or supersonic speed? What about pistols? Did this change much between the matchlock era and flintlock era?
2. Would subsonic rounds from a rifle be able to penetrate 1400s plate armor a significant amount of the time? What about supersonic rounds? Would this change much using a rifle from the matchlock era vs flintlock era?
3. Would subsonic rounds from a rifle be able to penetrate the (presumably thicker to defend against firearms) 1500s / early 1600s plate armor a significant amount of the time? What about supersonic rounds? Would this change much using a rifle from the matchlock era vs flintlock era?
4. Same as questions 2 and 3, but with pistols instead of rifles.