Bretheren: I believe I have narrowed it down to where I can fireform the correct cartridge with a small charge and a cream of wheat w/seal. Please see if my madness checks out. The bore diameter measures .250 when a proper micrometer is used. The 6.5x55 and now the 25/06 Rem. WILL NOT CHAMBER. The 250 Savage WILL CHAMBER. The .257 Roberts WILL CHAMBER, as well. Ergo... If the .257 Roberts CHAMBERS IT CANNOT BE A .250 Savage, as the .257 Roberts is TOO LARGE to chamber in a .250 Savage chamber due to the shoulder diameter being .414 on the .250 Savage and .430 on the .257 Roberts. Therefore since the bore is .25 caliber, and the chamber is too small to be a 25-06 and large enough to accommodate a .257 Roberts, by process of elimination it has to be a. 257 Roberts and even if it is a .257R ACKLEY IMPROVED, firing factory cartridges, merely fireforms them to an AI. The other three .25 caliber cartridges 25/20 and 25/35 and .25 WSSM don't enter into the equation for obvious reasons. What say you to this theory?