Mac,I've thought about cutting some 444 brass down the 445 mag length,and run it through the 44 mag sizing die,but I'm afraid of a stuck case when it goes over the web area(it would have to draw the thick part of the web down .010"). The 44 mag brass will also swell when fired in this chamber.The 445 brass seem's to hold up alright even after 4 or 5 reloadings.If NEF would just fix this on the new barrels they could sell alot more 44 mags.
My barrel bore checks out at .432" also,and the chamber is .460"when it should be .454".When you run the 445 reamer in the chamber it will not even touch the sides of the chamber. When mine was a 44 mag only,it shot best with the revolver load at max. Hope this helps.If I could find some brass with the proper deminsions (.460at the web) and a rimmed cartridge it would be a perfect situatiion. Digger