Any wall that has much substance to it has to be signed off on with it's construction design by a licensed engineer in most states.
Again, for most states, a wall or structure of over 4' in height is where the engineering starts...
4' ain't much of a wall.
If you pay for an engineered wall of 20' or more in height, it'll be expensive. Very expensive.
You are correct. He told us originally he had a range engineer but he failed to want to provide the guys name. The guy who he was name dropping was build a commercial range which has nothing around it and is commercial, we were told by the engineers I spoke with and had some friends who more in this field inquire with, none of them would sign off on this , not that close to homes and not that caliber, no one wants to tag that liability, which actually it was the one range design engineer who told us we should also make sure he has insurance on this range since he owns a gun business and is stating he is using this to site custom made rifles. This is for business use aside from his personal use we are not zoned for that.
Our county code enforcement agent said anything that needs concrete will need a permit. If he plans on going over 4 ft you need concrete and really because of the sand anything he puts up would need to be stabilized as it is the sand is washing away now. He didn't re-enforce it when he dug it out with anything so here in Florida where we are known for sinkholes this guy dug a hole for a range
