Dang.
So basically, you kegged your beer as soon as it hit a magical number which might or might not have anything to do with where the FG is supposed to be?
FWIW, My pales normally finish at about 1.008.
Could well result in extra carbonation, but also the amount of C02 uptake when force carbing like you say (which is the same as I do) will depend on how cold the beer is when you start carbing, how much residual C02 is in the beer before carbing, and how quickly your fridge will get the beer down to fridge temperature. This is why I only carb to about 80% using the rapid carbing method, and then let the beer come to full carb under dispense pressure which is balanced to carbonation pressure, which in my system is about 90kpa.
Next time, let the beer ferment until it finishes fermenting, and then give it a few extra days to condition. The yeast will clear up the beer after they finish fermenting it, and then cold crash for a day or 3 before kegging. Should take about 2 weeks total. The cold crashed kegging will mean the beer is at least at a consistent temperature before force carbing.
If your beer is currently too fizzy, then its probably over carbed. Disconnect the gas, then release the pressure, give it a shake, and release the pressure again. Repeat until its no longer too fizzy. Be careful not to spray foam everywhere.
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What dispensing pressure do you use?