, leave the poor lad alone, he is only looking for answers, something we have all done before ( some of us more than 25 years ago
Ok, i know your all bieng helpful, so he doesnt waste years of his life, but thats his choice? right?.
anyhow, try and find a copy of Gerald Cardews book 'Airguns from Muzzle To Trigger' and go to page '44' (Barrels and pellets) you will see that nothings new, and its all been done before, but it will be very informative for you
PS As a side note, you will/should find, that sizing UP will strip a ring of lead off the back of the pellet skirt, (As its far easier for the forces involved on the back of the pellet to do so, rather than to reform the skirt to the rifleing ) energy will always find the point of least resitance.
"you cannot change the laws of physics Captain" - Montgomery Scott.