Re: Chamber Question
Yes .030" is a huge amount in chamber dimensions, at the web (I don't think you meant head) I have no experience with you rifle in factory configuration so I can not comment as to weather that is original design or not. What you must remember is that a battlefield rifle is designed to shoot every case just once, not many soldiers wait around for the fight to stop so they can grab brass. Your cases are being worked excessivly at the web, and you may also have excessive headspace, exaserbating the problem.
You may be able to extend brass life by neck sizing only, check the fit into the chamber after neck sizing but before loading. After 3-4 neck sizings the fit may get too tight to function reliably and you will have to use your full length die.
Don't set the FL die up to meet the shell holder, start about .050 off and then test the brass fit to the chamber. Size a little deeper and try until it fits with minimal sizing.
Personally, I'd retire the thing.