2"= 63.5mm; 2 9/16" = 65.09; 2 5/8" = 66.68"; 2 3/4" = 69.85mm
As long as the gun has a forcing cone of at least 3/8" rather than a Step there should be no problem shooting 67mm shells as long as the pressure is proper for the gun. Do not shoot shells loaded to higher pressures than the gun was designed for, regardless of the length.
according to some threads the flues ithica is 8200psi. im not sure what the psi of the holland loads are. they say lite load. i have krupp steel barrels. no pitting. it is in excellent condition. ive shot polywad vintager no issues. about 25x i,m thinking about staying with rst and polywad. now what to do with these holland shells
