Depends what you mean by "normal" bolt.
The stock SP Ion bolt will be very inefficient due to continual venting of gas while the trigger is held down and the bolt is in the forward position. The orange unicorn kit WITHOUT the nano extreme add-on would have this issue also.
However if you bought the dual-tail-oring'd bolt with the Mech kit, then the marker should be pretty damn efficient. This should hold true for the Orange nano extreme kit.
How bad is the leak? Slight? Or gushing air? If it is slight, I still think one of your breech o-rings is worn, especially since it happened with both bolts you tried.