i seriously think its from consecutively "overtraining" them.
its back day, but the arms feel recovered?well,then its gonna be another arms day.
they feel ready to go 1 or 2 days later again?will be another arms day.
do about 30-50sets for arms every time.
they get wicked pumps in the most unlocigal times, during legpress even
it cost me a blown up shoulder but is all worth it

btw the all the same 1cc or 5ccs.not a difference thatd be worht it.2cc is the sweet spot before the lines fade.