"Seasoning" a barrel

So my gun shoots some pellets faster after the barrel has had a few hundred shots through it after cleaning it - about 24FPE clean and 27FPE "seasoned". I just cleaned the barrel again but since it's a single shot 50lb pull break barrel - Does anyone know a better/faster/cheaper way of getting your barrel to that sweet spot without shooting it there??

appreciate the suggestions.
 
"Jadocs"Nice, yeah I’m not sure if it’s a case of “seasoning” the barrel or if it’s the piston chamber warming up after a few shots that might give you the slight increase in power.
Nah, I've chrony'd it both ways with multiple pellets and see the same spike/drop each time. I'm wondering if there's something like carbon dust (?) I can sprinkle down the barrel to get the affect. I assume if I wash my pellets (I have before) it will slow this process down.