Did testing again today - I used the T2's reg, same barrel, same paint, pretty much the same speed (as close as I could get it) and found the numbers to be just about the same.
The T2 was 25 percent more efficient. It has to be either the hammer or the Spring difference.
I will start messing around with that.
I want to take 9 grams off a S6 hammer and try that next.