Ambulatory infusion pumps, pump assemblies, cartridges, baseplates, cannulas, insertion tools, and related components as well as combinations thereof and related methods. An exemplary medicament cartridge may comprise: a barrel defining at least a substantial portion of a medicament reservoir that has a total filled volume； and a plunger movable with respect to the barrel to controllably dispense out of the reservoir an amount of medicament of 0.1% or less of the total filled volume of the reservoir and with a single-dose precision of better than plus or minus 20%； and the precision is obtained within a dispensing period of less than eight hours.
