Griz,
My experience exactly. Not to mention the fact that most Marlins in good shape will shoot two inch groups or less at 100 yard, with factory 170 grain Remington Corelocts.
The sad boring fact is that a Marlin 336C, with a good 3 or 4 power scope, in 30-30, is all that anyone needs to shoot a deer (even a really big one) out to 200 yards. Sight them in for about 2.5 inches high at 100 yards, and they will be fine at 200 yards.
I have heard that the .35 Remington caliber is supposed to be a better killer, . . .but for me, I have never lost a deer that I (or my wife or son) ever shot with the 30-30, . . . . and really, . . . dead is dead. I will admit that most of them run (stagger) about 15 to 75 yards before piling up, but in the places I hunt, this is just not a problem.
Big Paulie