Make sure that the bolt that holds the limbs on is tight also, I used to
check mine about every 25 shots when I was shooting my quad 400
Just a thought.

Well , my knocks are parallel to the string . The arrows have the facory fletching - It's probably a couple of degrees offset . The arrow channel shows wear - How ever the aluminum was coated/colored has worn off . So the arrow rides against raw aluminum (it feels pretty smooth but maybe the friction is too much ). Just a couple of questions -1- The arrow retension spring , ths is the small spring that holds the arrow down against the rail , right ? How much pressure should be on this? 2-Should your string should have a significant amount of downward pressure on the rail ? Thanks .

Are you using lube on the track?

How much pressure should be on this?

Excal calls for 1/4" between spring and rail. Should work for your bow, you can check by loading an arrow and kinda tapping on stock while you have it pointed down. Arrow shouldn't move forward any at all.

I'm begining to think that maybe it's operator error . I hadn't thought too much about rail lube . I have been waxing the rail , then buffing it out . And maybe not frequently enough . How am I supposed to be lubing the rail ? And how often ? Thanks .

Depends on the amount you shoot,I check mine about every ten shots.

Just wax the rail and leave the wax on. Do not buff it out.i wax the rail on my Barnetts about every 5-10 shots.