I am lucky enough to have access to some property we run our business out of and I am going to put up a 200+ yard shooting range .

I am tired of loosing my arrows which run 10 bucks a piece then figure 10 for the broad head so I am thinking a nice sand mound to put behind my 3d target. Right now I am running the glendale full rut and plan on a block 4x4 next season. nothing wrong with the glendale but the block would be easier to haul around should I run out to the public gun range for some reason.
I am thinking 15 feet wide maybe and ohh I would guess 6 tall. Any idea how deep I should go to stop the arrows and hopefully not sink it till my fleatches get trashed? Also I know bow forum but how deep would it need to be to stop a 308 and a .50 cal muzzleloader?

Also any idea on how many tons I would need. I have a 1 ton truck a dually dump trailer and gravel yard down the road and one just up the drive from the property so hauling the sand is not a issue.