Need help with Talon erratic volocities

Try this. 1. Check top hat. Make sure 2 grup screws are tight. Check clearance. A quarter (.070) good starting point. 2. 2600 psi start fill ppressure. 3.power wheel on #6. Adj pw to aquire desired speed. Refill gun , shoot string and make adjustments. Wouud also to lube all o rings and perform basic maintance. All guns are different and this is a starting point. 

It sounds like you may have hammer chatter. Take the barrel, hammer and spring out and clean out the tube. Use some divers silicone on the hammer and that may fix it. 

I would change the two o rings first. Cheap and easy to do. Then check the top hat like shambozzie said. Just dont over tighten the tiny screws. They can push right thru and ruin the inside of the top hat.. i would also recommend getting an adjustable top hat as soon as you can. It made a huge difference in my condor ss.