Ok, so I picked up a 1.5-4x20 for my nephew. Its a Duplex reticle with no BDC, seems pretty solid for a $279 scope. Taking him to the range tomorrow afternoon to sight it in. My question is regarding the turrets, how do you reset zero with it after sighting it in? It doesn't have any set screws, and I am figuring there must be a simple solution I am missing. The instructions are vague at best, and I haven't been able to find jack on the web. Any help would be appreciated.