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stuka762... "Tipping" the powder can isn't the only way in which excess pressure can be produced. On the face of it the load you quote should be safe in most rifles, so look at your rifle and your ammunition for the answer.
A few ideas:
Closely look at the barrel, preferably with a borescope, for signs of heat checking and/or jacket fouling- any signifigant faults just ahead of the chamber can lead to very high pressure.
Check the neck diameter of the loaded cartridges against a chamber cast. If there is not 0.0015 to 0.0020" clearance minimum this may be the cause of the poor case life you are seeing. Critically check the cases for burrs at the case mouth.
Check headspace.
Check the diameter of a signifigant sample from your current lot of bullets. It is remotely possible that 0.311, 0.318, or 0.323" diameter bullets have become mixed into the lot you are using.
If all of the above prove OK, have a a machine shop with a ROckwell Testing machine part off the body of 10 cases just ahead of the web (keep 'em cool!), and then face the remainder of the case until it just "cleans up." I'd consider an average reading of greater than Rockwell 86 F with no case softer than 84 F to be acceptable.
Bob
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