Sorry I couldn't find my original post so here it is again. I am posting today because, problem solved!
My son has a Remington R25 chambered in 7mm-08. He bought it used while stationed in Alaska. You know those kind of deals where a guy is moving on and needs cash. As it turns out every fired case has over pressure issues. This was happening with all brands of factory ammo. One particular issue is oversized primer pockets. One of our members sent me an email about checking the chamber neck size by measuring a spent case. He stated that the neck size of the chamber should be .316-.318". And the neck size of a fired case .315" or less is dangerous. As it turns out my sons fired cases have a neck size of .3145". Now that the problem is identified it is time to come to a resolution. I recommend changing barrels and go to 6.5 Creedmoor. My son likes the accuracy of this barrel, .75" at 100 yards. He is considering reaming the chamber.

Glad you have the answer to the problem!