First post here I hate to start with this question. I recently acquired a gen 1 Tac that was pretty much unfired, and has been sitting for the past 8 years or so. I was very impressed with the speed and accuracy on my first 20 or more shots with it on my range. Tight groups out to 60 yds so far. Then in one shot the other day I went from 2" groups at 50 to totally missing the bag by at least 10-15 yards....based on the way the next attempted load would've been pointing had I not seen the obvious and stopped. The nock had suddenly moved about 3/8" to the right, just after putting previous shot in the bull. Cocking sled shows it's now way off, and IDK exactly where the timing reference marks were before, but now the one on the left side is about a string width showing out from beneath the cable. The right hand side is directly below it. A buddy of mine insists it's possibly a stretched bus cable and says I need to fix the timing with twisting cables. I hope I can find someone here familiar with this problem and on these particular bows. Please help, any guidance greatly appreciated, I was all ready to hit the woods with it for deer...now this. Already been through a nightmare just trying to get some good bolts to shoot with it. Thanks in advance for any help. Love the forum.