thoughts on the .440 corbon chambered in a GI .50gi upper, i would guesstimate it is somewhat possible. one would need, a glock 20 or 21, with a .50 gi upper, based on the .45, it has a .45 case head. the .440 corbon is a necked down .50 ae, which itself is a derivitive of the .44mag, same case head. so the .50 gi upper should grab hold of the .440 corbon case and extract it. also eject it. now for the cartridge length of the .440, is it way out of the 25mm length of a 10mm or .45acp? yeah it is, its 32mm long. would it be possible to flare the ejection port of the glock to allow the .440 to pass through? would the frame fit the round?