The string on any bow or crossbow is a wear item. If your string fails, you are looking at potential dryfire damage so check it regularly and change it when needed.
If a string is only worn on the centre serving (the section of the string that travels over the barrel surface and pushes the bolt, wrapped in serving thread), you can either replace the string entirely or reserve it (replace the serving section). In the case of reserving the string, there are online tutorials that explain how. It may also be a blog topic here, in the future.
Whether a reserved or brand new string the procedure is the same: first you can apply string wax to the strands while the string is loose as this will give you greater protection than applying wax once the string is taut on the bow limbs.
First, loosen and remove the screw at the rear of the magazine so that the magazine can be lifted away from the barrel a little bit. Next, put the limb end caps on both ends of the limb. Now take the stringing aid ( a heavy black cable that is plastic coated). Take the loops and place them on both end caps, seating the loop in the innermost groove on the end cap.
Now you can cock your Stinger II. This should not be difficult as the stringing aid is much longer than the string itself and therefore does not pull the limbs as far back when used to cock the bow.
You can now start fitting the string. First twist the end loops a little to make them narrower. Take one of the the ends, and pass it through the stringing aid loop and then place the string’s loop over the end cap in the outermost groove. Here you can twist the entire string about 4 times with full turns, what makes it a little bit stronger. Now pass the string between the barrel and magazine to do the same on the other side. Remember to make sure the string remains twisted 4 times and that you pass it through the end loop of the stringing aid before securing it to the end cap.
The string is now in the correct position, but remains untensioned. To release the stringing aid you have two options: either grip very tightly and manually lift it out of the retention groove (the limbs will pull so be ready for the sudden jerk). This provides plenty of resistance for the limbs and avoids a dry fire. The other method is to again grip the stringing aid tightly with your hand and use the trigger with the other to unseat the aid and release the tension.
Whichever method you used, the tension in the limbs is now passing through the string and it is the stringing aid that is now untensioned. Unloop it from the end caps and remove it from between the magazine and barrel. Finally refasten the magazine retention screw.
You can now cocking your AR-6 Stinger II to check for function. Once more, grip the string before releasing the string to avoid a dry fire but be aware that the tension and forward motion of the string will be with the full power of the limbs so make sure your grip is strong and you are tensed and ready for the sudden release.
If you want to replace an already used or worn string, you must first lift the string over the two silver cocking rods before attaching the stringing aid. This way, only the stringing aid is tensioned, while the string itself remains in a loose state. This allows you to easily detach the string from the limb end caps when the stringing aid is tensioned, pull it through the loop on both sides and remove it before installing the new string.
You have now changed your string and you are ready to continue enjoying your Stinger II.
If you have further questions there is a lot of information on our FAQ page.