Swingline staple guns, while discontinued, remain a popular choice for fastening lightweight materials. There are few Swingline staple guns available for purchase in brick-and-mortar stores, but they are still readily available online. Although Swingline hasn't produced any staple guns since 2003, instead choosing to focus efforts on office staplers, the company still manufactures staples specially made for their staple guns. Loading a Swingline staple gun is a very straightforward process that takes little time and effort.
Determine which type of staples your staple gun requires. The light duty Swinglline staple guns will use Swingline's model 101 light duty staples. The heavy duty Swingline staple gun will require heavier staples. Consult your owner's manual for the proper staple measurements. Popular heavy duty sizes are 1/4 inch and 5/16 inch.
Hold the staple gun in one hand with the front of the stapler pointed toward you. Be sure to keep your hand off of the trigger handle. Find the release latch at the bottom of the gun. Sometimes you must squeeze both ends together to release the gate. If the gate does not release immediately, gently pull it downward until it is at full extension.
Place the staples into the now-exposed channel, with the sharp ends pointing toward you. If there are not enough staples to fill the entire channel, be sure to slide the staples all the way to the top.
Push the gate back toward the head of the staple gun, making sure that the gate itself runs through the middle of the staples. Push the gate until you hear it click into place. Fire the staple gun once or twice to make sure that the staples are loaded correctly and firing one at a time.