Re: setting up my hha
It could be as simple as a change in the placement of your head or cheek to the eye piece of the scope. It's very important to maintain the exact same distance between your eye and the scope each time you shoulder the crossbow. It usually doesn't cause that much of an adjustment on the HHA, but it can.
One of the best ways to maintain the exact same positioning is to add a check rest to your stock. The stock is an AR15 type stock, so you can go to Cabela's or Brownell if you prefer and do a look up on AR15 Cheek Rests. They are very inexpensive, snap on and do a nice job.
Because the HHA Optimizer Speed Dial adds more height to an already high Weaver Rail Mounting System on the AR15, it's difficult to maintain a good head / Eye alignment on these weapons. A raised cheek piece is the best way I've found. Also, if you're using the UTG / Leapers Scope that comes in the TAC15i Crossbow package, it doesn't help that it has a 4.5 inch eye relief. In my opinion, this puts your head to far away from the scope to maintain good consistency. I much prefer a 3 inch eye relief and a more compact scope.