Something I meant to post for BM last night, but forgot. The Mausers in 30 - 06 that blow are are fairly easy to Identify they are called 03 Springfield's.
It has been known for a long time,the early production had some heat treat mistakes that led to brittle receivers. There is a specific serial number range that should be available from NRA, American rifle has mentioned it a couple times and it may be in a back issue of Shooting Times.
IIRC (?) it was the first 250,000 from Springfield and the first 20,000 from Rock Island.