I cannot say to the type of powder you have used,for I use 4064 and Varget for my 308 loads.Now with that said I load a 175gn SMK with 42gn of Varget,and my load comes in at around 2544 fps.My drop chart shows a -4.66 drop at 200 with a 100 zero.So I would say that your load is a little faster than mine.I am guessing but you load sounds to me that its in the 2700 fps range.
the choice of 100 yards is OK for a zero,but most who hunt like a 200 yard zero.All this will help with is that it will allow you to just point and shoot from 100-200 yards,without having to do anything.Me I too like a 100 yard zero,for I have the target knobs to move up/down when needed.Or I just use Kentucky elevation out to 300 if I need to.( for deer hunting only ) BUT one must know to what the bullet will do at a given range or its a waste of time.
and as Bart B. said,if your rifle will hold a 1/4" group at 100 it will grow to a 1/2" group at 200 in general,but seen a few to stay a 1/4" a time or two out to 200.Different combos in bullet and powder choices will do different things,even changeing the OAL will make a bullet change the group size.
life is great but its better when you can own as many guns you wish to own.for me I haven't bought enough yet.