i currently reload for my 6.5x55, a tikka t3, i use 46.5 grains of R19 (under max load), federal brass and primers and 129g sst bullets. My concern is that i am noticing a stripe on the cases where the case head meets the body, i am not seeing any pressure signs. this does not happen on all cases probably about 20% of them.
When i resize i use a full length die but i have backed it off a bit, so that all cases will chamber easily but it does not touch the shell holder when the ram is up.( i read somewhere that this was better for the brass, a sort of half neck half full length resizing operation.)
the only info that i can find points towards excess headspace as a culprit for this, but i was wondering could it be bad brass, bad reloading?
your expertise is very welcome.