Bonanza,

I have a pre-war (1939) Sauer & Sohn sidelock drilling with separate rifle barrel cocking in 16/16/8X57JR and a Greifelt pre-war (1939) drilling in 12/12/8X60R. Both use the smaller .318" bullet and both are great performers. I suspect that the real problem with the .323" bullet is the fact that the larger bullet means that the cartridge is .005" larger in the neck and the chambers cut for the older .318" bullet simply have too little neck clearance.

It might be fun to take a bolt rifle with the J bore and rechamber it for the S bullet, just to see how much of a difference it made in pressure. After all, .005" is only 1.5% of the .318" bore diameter, and I know of at least one instance of a .308" bullet being shot through a .264" bore with no ill effects, and the .044" difference represents a 16.6% increase in bullet size over bore size.

However, as has been pointed out above, the correct .318 bullets are not all that hard to obtain and bringing one of these beauties back to life is well worth the effort involved. I would want to mount a scope on that rifle, but I assume you know someone competent to do this. Looks like a great buy!