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Point the gun so that the area where the nails come out of is facing away from you. Then, look at the back of the gun for a small metal rectangle with 2 indentations on the sides and a small hook at the top or bottom. This is the release for the pusher rod. If you're having trouble finding it, trace from where the staples come out of the gun to the rear area, which is usually a straight line. Place your thumb and forefinger in the indentations on either side of the pusher. Then, push the rod forward and down if the hook is on the top of the rod. If the hook is on the bottom, push the rod forward and up. Once the hook is unlatched, pull the rod completely out of the gun and set it aside. If pushing in one direction doesn't work, try the opposite direction before pulling it out. In most cases, you'll be able to see the hook on the rod as it unlatches when you push the rod in. Take a row of staples and position them so that the legs are facing down with the staples on top of the rails inside of the chamber. Then, let the staples slide all the way to the front of the gun. If you're going to be using a lot of staples for the project, it's a good idea to fill up the chamber with staples, leaving only about 14in (0.64cm) of space. If you don't slide the staples to the front, they can get stuck when you reinsert the pusher. Position the end of the pusher without the release mechanism inside of the chamber. Hold the rod straight and push it into the chamber, hooking the back of the rod in place at the top or bottom. With some staplers, you might feel some tension while you're pushing the rod in. This comes from the spring on the rod touching the staplers. Keep pushing the rod until you can hook it into place. To make sure the staples are loaded properly, fold a piece of paper in half or use a scrap piece of wood or fabric. Place it under or inside of the stapler and pull the trigger to release a staple. Make sure the staples are firing smoothly with no jams. Try to test the stapler on the type of material that you'll be using for your project.
Locate the pusher rod at the back of the gun. Push in on the rod and pull it out to remove it. Load the staples legs-down over the guide rails. Reinsert the pusher until it locks in place. Test the staple gun on a piece of paper or wood.