Does your t3 have a front reg on it?
It could be that your inferno is still sprung/valved for winter.
Markers running on CO2 (especially blow-backs) tend to need different spring/valve combinations during warm and cold weather, as the CO2 doesn't expand as much during the winter.
During the winter, the CO2 expands less, and is at a lower pressure, so more gas needs to be let into the marker to propel the paintball at the same velocity. Once the weather warms up, your CO2 is at a higher pressure, but if you still have the winter springs/valve in, you are still getting the larger amount of gas through, pushing your velocity up.
If it gets too warm for the winter kit, then you end up shooting about 3 feet, as the pressure in the valve is too high for the main spring to open the valve far enough.
IIRC the summer valve is the black one, but I'll try and double check that for ya.
There is also a ague possibility that the main spring is hung up inside the body of the marker, and is stuck so that the velocity adjuster is not in contact with it, but that's probably quite unlikely.