Ok, tacotime, I think you need to fill in some blanks here. What ammo was the rifle sighted in with at 100yds? Did you change ammo when you went hunting? Did you confirm 100yd and 50yd POI at the same range session with the ammo used? Given the possible variables, if you sighted in at 100 with the 300's, then switched to the 405's when hunting, that could account for the rise in POI. If you didn't change then it may actually be that high at 50 and you just didn't know because you never confirmed that at the range. A different rest or hold will move POI a bit, but not that much at 50yds, so I would think it's either the difference in ammo or the scope shifted. I sight my rifle in with the ammo that I hunt with at 100yds and then fire a couple of shots at 50 just to know where it's hitting up close.