I have tried five different barrels so far including the ronin katana adjustable, 14 inch Dye, lapco big shot, aci, and stock. Out of all of these nothing comes close to the flatline. This by far is the best shooting thing I have seen. I was hitting just about every thing I shot at distances other barrels couldn't touch I have tested many different paints in the above barrels and nothing came close to the flatline's distance and accuracy.
It is top heavy and I did notice rapid fire decreased accuracy but still way more accurate than any other barrel.
I must say this is the best barrel I have seen. If you want one I recomend looking on line, not sure if I am allowed to say where but I found mine for only 89.99 plus 6.00 for shipping. I spent more on the dye and the flatline was better.