The bases were too fat to go in. Is this where a small base die would come in handy?
The base of the small base die will never make it to the base of the case if the base of the case is the head of the case.
My shell holders have a deck height of .125"; that means the base of the case can not be sized. If I was curious about the head of the case being upset I would turn the case around and shove it into the big end of the die.
I have cases that have been hammered with heavy loads, the heavy loads crushes the case head. Under normal conditions and factory loads the case head upsets .00025", in theory the case head would expand .001" when fired 4 times. And then there are cases that are thought to be soft.
The small base die has nothing to do with the small base of the case, the small base die is smaller in diameter at the base of the die. Then there is always that discussion about how much smaller in diameter the small base is than a standard die.
I have small base dies, my small base dies want to keep every case I shove into them. I measured them and they are smaller in diameter than small base dies.
Then then there is the M Garand, the M1 Grand shot the same ammo as the 03 and M1917, the difference between the 30/06 chamber and the M1 30/06 chamber was less than .0005". I am told the old guys could not hold tolerances that close but it is in the book.
I have an old gage that measures down to .000005", to me it was useless so I modified it to start measuring at .0005".
F. Guffey
The case gage measures fired and, new and full length sized cases, again turn the case around and place the head of the case into the case gage. Again there is no way to size the head of the case below .125" from the head of the case because of the deck height of the shell holder. Meaning if the case head will not fit the case gage the case head has been crushed/upset.