@ 10:33 pm (GMT)
Nathan FosterHi Radley, don't blame the belt, this has nothing to do with the issues you are seeing.
For starters, the brass you are using is a pain in the ass, both Nosler / Norma and Federal. Both are weak in 7mm rem Mag. If possible, change to Win brass.
If you continue to have extraction issues, it will be a primary extraction problem with the action, not a brass issue. Or- it could be a reloading method issue. None of this has anything to do with the belt on your brass. The area just behind the shoulder of your case is more of a concern.
Sorry, I have lost track of this thread so the next info could be moot. There is a chance your neck die is extruding cases or shoulder bumping and widening the diameter just behind the shoulder.
Suggest you try the Lee ultimate die set for this. It comes with a body die. You can drill out the neck area of the body die if need be so that you can size the body without losing and concentricity.
Careful with blame allocation. Let go all assumptions as these are doing you no good.
Look at reloading methods.
If primary extraction is at fault, bolt handle may have to be shifted forwards to increase camming power against the rear of the action. Could possibly talk to PTG about an entirely new bolt. That would be the quickest route.
Empty unprimed / unsized brass won't cycle? Possibly both a very tight chamber combined with poor primary extraction. case goes in with a tight fit but won't come out because there is no camming power. The rifle may need to go to a gunsmith to have the headspace checks and primary extraction explored.
My hope is that the answers are quite simple. It may be that small things are causing problems. Well thats what I am hoping anyway.