11mm (0.433") is smaller than the 7/16" (0.4375) punch. An 11.5mm (0.453") punch would about right for those desiring a .45 caliber punch.
The Buffalo Arms 45PISTOL
punch is .455".
My smallest .44/.45 revolver has a 0.447 chamber supposedly but the felt wads are flexible enough to used for it on up to my ROA's which have a larger chamber diameter.