Somewhere some years ago I came into possession of a small amount of 45-70 brass (non-magnetic metal?) that is just a shade off from brass of known origin. Some are stamped WCC - 45-70 GOV and weigh about 158 grains, the others are marked WCC 45-70 MK1 - 1943 and weigh about 147 grain. Winchester brass weights about 168 grains and my R-P brass weights about 186 grains. Does anyone know what this stuff is and should I use it to reload. It looks sound enough for loading light loads for my 1884 trapdoor - wouldn't load hot. Comments??