Inconsistent shot strings

Hi Guys

I’ve had my talon for a few weeks now. I hand pump in my basement. Humidity is an average of 60%. I brew and ferment beer in my basement, adds to the RH.

Noticed a slight vapor coming out of my breech after shooting. A few days later my Benji HPA pump stopped filling on the up-stroke and felt like a vacuum. Talked with Sun Optics, got a desiccant filter and set of o-rings. I installed the desiccant but didn’t open the pump. The next day it resumed working like normal.

I’ve had some issues with the power wheel from day one. Specifically that it doesnt really do anything. Yesterday I made some adjustments to my top hat. It’s now spaced so that a quarter provides slight resistance when measuring the gap. I’ve also installed an o-ring with a thickness of 1/16″. I believe it was a #6 from Home Depot. Adjusting the top hat and installing an o-ring made an immediate impact on the power wheel. Whereas before it had previously very little impact, I can now adjust between 500FPS around #1 and 850FPS around #10. After adjustments it takes a shot or two to settle down but then it provides, mostly, consistent results

Ran some shot strings over the weekend. Out of 10 shots, 8 would be 820-840 (desired) but on average 2/10 would drop down to 720-740 FPS. A drop of 100 FPS seems pretty extreme.

My question: What is causing the erratic behavior? Could there be residual moisture in my tank from pumping before the desiccant? Is there moisture trapped in my pump still? Could this cause inconsistencies? The 8/10 shots that are in the FPS range I expect are very consistent. Far better than before the Top Hat adjustment and o-ring install. I also experienced the 100 FPS drop in power BEFORE adjusting the top hat.
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