My gun has always from day one punches out 2 nail and jams up or not, is there an adjust ment for this problem

Nailers will double fire or at times, the driver will hit two nails with one stroke. The first issue is caused by sensitive trigger or worn orings and the second problem is caused by faulty nails (too close together in strip ) or the driver is bent slightly allowing the driver to strike the head of the second nail in line. One way to prevent double fire is to use the single trip trigger (usually white plastic). With this trigger, you must lift the gun off the work, release the trigger and press the gun against the work and pull the trigger. If you are using the black bump fire trigger and it double fires, replace the trigger valve. The issue of the driver blade hitting two nails with one stroke can be solved by examining the driver blale for damage. The blade should have a taper on the side that faces the nails. This taper is there so that as the driver hits the first nail the taper will gently push the rest of the nails slightly into the rails out of the way. If generic nails are used, make sure that the nails are designed with the proper spacing and angle. Easy test. With the gun on its side, place a strip of nails on top of the rails with the heads aligned with the angle of the rails. Move the strip of nails so that the first nail is in the path of the driver and the heads are still aligned with the rails. The first nail should align perfectly with the angle and path of the driver. If the head of first nail is in the path of the driver however the shaft of the nail is angled toward the rails, the driver blade may hit two nails. If the point of the first nail is in the path of the driver and the head is angled back toward the rails, you may have miss fire. If the nails are perfectly aligned with the rails and the path of the driver and the driver is hitting the second nail, grind more taper at the bottom inch of the driver. Good luck