It is called a uni noc and will work in place of flat or half moon nocs. Those are the nocs that come on tenpoint bolts. They are also not stronger than nocs used on excaliber bolts which are flat metal nocs.

If I read right, you have two or three different make arrows you are shooting. Do they all have the same style nock? Is it the style recommended by Carbon Express? Using the wrong style nock, especially on a compound, or loading an arrow with half moon nocks the wrong direction can cause semi dry fire or even dry fires. As said, make sure arrow is loaded all the way back against the string, and be sure if using half moon nocks, that they are properly oriented to the srting.

I am using a rope cocking device and the nocks are all half moon on every bolt bought, which is what is recommended for the Carbon Express. Taking it out again this weekend with better knowledge and more time to shoot it.

On my Excalibur there are 2 "fingers" on the latch that drops down to hold the string when I am cocking the x-bow. The first few times I pulled the string into place with the rope cocking device I did not get the string behind both "fingers" due to not putting equal pressure when pulling back with both arms. I would think if the string was caught only behind one "finger" then it would cause issues with bolt flight and accuracy.