Handguard too fat

[INLAND44]

Sounds like you have a warped hand guard. The original hand guard had a larger radius relief in the center so you could see the whole front sight. Unfortunately these tended to crack down the center because the wood was rather thin there. So, they revised the relief to be more shallow and narrow. So you have two problems; a warped hand guard and a high center cut. You can wrap sandpaper around a wood dowel of a certain diameter and expand the center relief. You'll have to stain and oil it after that.