Powered fastener driver

A fastener driver comprising:

• a housing defining a head portion and a handle portion;
• a drive mechanism positioned within the housing;
• a firing mechanism including:
• a primary guide member supported within the head portion of the housing,
• a secondary guide member spaced from the primary guide member and supported within the head portion of the housing,
• a piston slidable along the primary guide member, wherein the primary guide member extends through the piston,
• a driver blade attached to the piston,
• a biasing member configured to move the piston and the driver blade from a top dead center (TDC) position toward a bottom dead center (BDC) position;
• and
• a bracket coupled for movement with the piston, the bracket defining a bore that is sized to receive and support the piston on the secondary guide member;
• a lifter assembly operated by the drive mechanism and having a pin, wherein the pin is configured to be rotated by the drive mechanism and engage the bracket to return the piston and the driver blade towards the TDC position, against the bias of the biasing member;
• and
• a frame located within the housing and configured to support the lifter assembly and the primary guide member.