Std. op.proceedure might work, but then it might, in this case, lead you to pitch brass still useable.
What you want to look out for is "wiredrawing" which can cause case failure through head spearation. Try this method of checking.
Take a paper clip, and straighten out enough of it so that the straight part is longer than the cartridge case. Bend a short "l" at one end.
When this "tool" has been made, use it as follows. Insert it into the fired case so that the "hook" is down against the inside of case head. Move the clip so that the hook contacts the case wall. Slowly, pull the clip out. If you feel like the hook simply comes out through the case neck, the case is alright. If however, the hook feels like it "falls into a ditch", then climbs out, your have found a stretched spot, where head separation will likely take place. Trash any such cases.
You can extend the life of cases by not setting the shoulder back any more than is necessary for easy chambering of a loaded round. With a bolt rifle, you can lean on the bolt handle, however you do not want to try this with a self-loader such as the M1-A, no bolt handle.
You can check this by removing the operating rod and spring, and moving the bolt by hand, slowly and carefully. Adjust your sizing die so that the bolt will close, when moved by hand, on a sized case, then lock your sizing die. You should only have to do this once.
With the rifle you are using, you might be better off using military cases, than commercial brass, due to the rather violent extraction cycle of the rifle. The military cases are heavier, thicker walled, and therefore a little tougher.
Hope the foregoing helps.