Hi guys. i have done same changes for my Vulcan , and i am happy about it. i have tite valve spring 1/4 turn and the gun gets much better. more quiet, more accurate and more powerful. write know i have 270m/s and i steel can go up or down... i know that on different velocity is different bc and the highest is not allways best. so i will try to find out whats best velocity is for my gun.