Had an idea for this myself. Was going to use a Measure laser sensor With a mounted laser as red dot With Arduino with a gyro and hud to show gun angle and a button in the trigger that activates on light press before fire to range select the target.

Was going to use a moded acustrike raptostrike with stefan worker kit so its accuracy is higher as reg nerf darts are crap and their fire variation is too high.

My head space is the button would Be semi held at the trigger. To take current angle and distance of gun and then the Arduino would provide a hud display of the optimum angle to adjust to along with a percentage of likeliness to hit target, as the dart tends to be the main variable Id do some number crunching based on a average Measurement calculation of about 10 Bullets The closer thr target the closer the accuracy Average should  be and if successful id move onto the likes of doing a similar mod for a hyper fire. But for The hyperfire trigger would run when the motor is activated And run on a 5 second loop as it collects current range and angle. In a perfect world the laser would stay on target calculating the optimum angle on the fly but i cant see that easily acheived unless the laser and range attachment hung from a pendulum to keep it at a constant level while the gun is tilted to compensate to calculate its angle. This how ever woild mean you couldnt use it to target low lying targets with it from an elevated position you would have to raise the gun up n down to the targets approximate height and also angle up to hit the target.

Looks like an old project did you give up?