All possible causes of bolt stick?

[AGDRetro]

Well I've thrown in my Cocker for a new RT Mag (Karta body on the way), and my only real concern is ensuring that my Mag will serve me reliably on the field, especially in a tournament setting. My last Mag had some serious bolt stick issues that preventing me from keeping it much longer than 2-3 months... this time I'm not gonna give up, I love these guns so much! So basically I need to know what can cause bolt stick and how to eliminate it as a possibility on the field!

This Mag is gonna have an X-Valve with Level 10 & ULT, so knowing that is there anything else you feel should be added to my list of possible bolt stick influences? So far I have...

ULT or Level 10 NOT properly tuned
Wrong bolt spring
Ball detents catching bolt

[REDRT]

With the LvL 10: Too tight of carrier or not enough shims could cause bolt stick.

Tightening the field strip screw too tight could cause sticking issues due to alignment

Paintball hull getting jammed in with the bolt. I had that happen to me alot with the LvL7.

That is all I can think of for now.