You’ll need a solid footing (compacted soil or stone depending on ground conditions). First tie needs to be below ground and if you’re in an area with really cold temps, it will need to be below the frost line. About 2/3 way up, you’ll need some type of tie back to deadmen. Treated wood or lond ties would work. The length of the tie backs should be at least the height of where they are in the wall face. As I stacked the ties, I would offset the next course a little; maybe ½”. That will give the wall some batter. The soil used to backfill needs to be some type of well draining soil (exp: sandy soil would be great; fat clay would be bad). A perforated pipe with some stone around it laid at the toe of the wall would be a good idea.
If you’re shooting at a target that stops the bullet (like shooting steel) and the ties are just there to stop misses, then this would probably work great. If the ties are there to stop all bullets, you’ll need to design it where single ties can be replaced without dismantling the wall. That will add a lot of expense because you’d probably have some type of vertical frame and attachment hardware.
Best route may be to just keep it soil and maintain it with a tractor w/ front bucket or hire someone with a bobcat to come out as needed to freshen up the berm.
Good luck.