When it comes to hunting boots what does 200, 400, 600, 800+ grams of insulation equate to in terms of weather?

That's a personal question that involves how cold do your feet get, how quickly do they get cold and what type of socks are you wearing?

I can sit on a stand all day long in normal hiking boots, with normal socks, provided the temp is about 45 degrees. If the temp is between 38 and 45 (or so), and I'm sitting, I will definitely wear thicker socks. If I'm walking, I will wear normal socks.

My recommendation, based on the information you provided, is the 800. You can always change to thinner socks if your feet start sweating.

Well I never saw or used the weight designation when looking for boots. (don't hunt anymore)

But I would stay in the lower half of the 200-400 range. 0 degrees is cold for sure, but what if you choose too much insulation and your feet begin to sweat? Better to have cold feet than cold wet feet.

Really depends on how tolerable your feet are to cold. I use an 800 gram boot in temps 45 deg and up, and if it gets colder I use a pair of wool socks with them. So if it were me, for those temps I would definetly get an 800, if not more.

I bought the rocky's marauders 2 with 1200 gram thinsulation and I absolutely love them. They were well worth the $150. They are really comfortable and I can sit all day in 15 degree weather. I like that they also let your feet breath without getting cold.

After buying these boot I have definitely learned not to skimp on the boots you buy.

I'd think 800, but only because I always get cold feet when I hunt.