I have a parker terminator 150lb that i have had for 3 years now. I guess the crossbow is about 5 years old now. Anyway it has always been a tack-driver but at the end of last season I started to notice the accuracy going away a little and this year I have been shooting it some and it isnt impressing me like it used to. I used to shoot 2"-3" inch groups offhand at 30 yards and now im lucky if I can shoot a 8" group. I noticed the string looks like it is coming un-wound and the center serving looks rough along with the end serving around the cams. I am hoping that the worn string is the answer to my problems. I was just wondering if any of you could share some info. thanks.

I would say it can't be good if all your servings are starting to unwind. I would highly recommend checking out Viper-X bowstrings. They make awesome strings that won't creep or stretch and the serving life is unbelievable. Check em out www.viperxstrings.com

Crossbow strings should be changed after about 500 shots.
It sounds like it's time to change your string.
Parker makes a Red hot accessory sting for you crossbow.

What Urban Legend said very good advice!

Change your string and cables and check the stock bolts for tightness. The 150n Terminator I used to have was a very accurate bow...still wish I hadn't sold it.

My serving went bad on my Horton and had to replace the string and found out the old string had stretch 1/2 inch. The shop was out of the oem string so I went with a custom and what a difference in quality.I will have to shop around next time on cost.

I hope you are back to tack driving soon!