Back in April I picked up an SR 556 Takedown. Over all I like it but have had trouble zeroing the iron sights. While the windage is fine it consistently hits low (2 to 3 in) at less than 50 yards. At 75 yards it's much closer to the bulls eye but the front sight post is as low as it will go. Ruger has sent me a new front sight which gave me the same results. I had similar results when swapping the sights out with my friends AR. I did have some improvement when I moved the front sight off of the gas block and onto the front most position of the upper. Has anyone else experienced anything like this? I can hit the center of the target at short range but have to place the front sight post completely over the target. Any advice or info is appreciated. Thanks.