I have a brand new 2012 (well two months old now) Marlin 336 and it is one sweet ride indeed. As for cast, that is pretty much all I shoot out of them. During the summer, some very wise folks on the Nutz advised me to get a Lyman neck expanding die for the 30/30 as my regular die was likely the culprit with my cast reloads. Lo and behold, they were completely correct. I sold my first 336 on account that the micro-groove was the issue, but that assumption and presumption from other fellows on here was completely wrong.
As for the Henry, check your headspacing. I bought one, returned it, bought some gauges and tested four more in the store (out of the box), all of which failed on the field gauge. They allowed excessive slop between the rim and the bolt face. The result was popped primers at factory loads. My Marlin, or the former one I bought, does not have that issue. They would not close on the NoGo gauge. Other than that, they were ok, except for the annoying tube reload.