Shimming the two-piece bolt with a STEEL shim has always been the fix for this chronic problem with the 23D, and it seems to me that it is the only practical one.
The action wasn't designed for more pressure than the standard Hornet of the time (and maybe not even that, given the number of shimmed ones out there....) and certainly not for the extra pressure you can cook up in the various "improved" versions.
We now talk about "K-izing" Hornets to "get better case life," but back in the day they were generally looking for more case CAPACITY and thus more velocity--and more pressure.
I don't still have a copy, but if I remember correctly (maybe not) Frank de Haas had something to say about this in his book on "Bolt Action Rifles." He may have even described how to shim this action properly.
Anybody got a copy to have a look-see?
