Recently, a good friend of mine got his string replaced on his bow. When he had his string replaced he replaced his peep site as well and had a new one tied in. As he started shooting his bow after the work at 15 yards he noticed he was shooting slightly right and a tiny bit high. Yesterday I had him over so he could shoot his bow at further distances with me, while shooting we found he was very erratic and was shooting very high. I figured between all the work he had done on his bow and the fact he hadn't been shooting distances lately was why he was off.
Well today he pulled his bow back out and was shooting and now he is shooting almost a foot high at 15 yards. Upon further inspection of trying to figure out what was going on he noticed that the area where peep was tied in had gotten bigger. He discovered the peep had slide almost an inch up his string (Pictured below). This can drastically change how and where you are shooting.
As you can see the top knot holding the peep sight in place has slide up the string almost an inch. There are two likely causes for this, either or both could be true. My first guess of the problem would be that every bow string has so many twists in it when installed, some of those twists come out as the string stretches after shooting. When this occurs you will sometimes notice things that are tied in but still able to move some like peep sights and string silencers can move around some. This is likely what has occurred in this situation with a new string. However, the other option which could also be secondarily contributing to his problem would be whomever tied the knots did not tie them tight enough. I myself have been guilty of this once or twice, it could happen to anyone so I do not discount the ability of the person who did the work.
The solution is my friend is going to get me to help him re-adjust his peep to the proper location and tie in a new top knot to ensure the movement stops and he can finally re-site in his bow with confidence that his elevation will not keep changing.
This problem can really be a hard one to realize and can cause you to wonder why your bow is shooting super high or low and because the peep can move both up and down once the knot slips it can produce erratic results each time you shoot. Most people do not find this problem until you find yourself having to adjust your shooting style so you cannot see out of your peep. Normally by then you have moved your sight and possibly done other things to try to correct your accuracy problems. Plus if your like my friend it can cause you to screw up arrows from missing the target. It is always worth checking periodically throughout the year that nothing on your bow has slipped or shifted from vibration or from shooting. Granted this is not a super common problem but I wanted to pass this information along in hopes it helps out those people who do run into the problem!
Have you ever had a similar problem? How did you figure it out?