My sons rifle has the prototype and has over 2,000 rounds through it. His rifle is extremely light, soft, flat and fast. Stays on target better than my rife with half the weight. Mine is JP barrel, LMOS BCG, silent capture spring and more. Don't get me wrong. I love my rifle and it shoots great but my next build will be a Whiskey Arms build. I will be replacing my JP LMOS BCG with a Whiskey Arms LBC soon. Will Wallace is a great guy and is very involved in our sport. If you are ever at the Texas Multigun monthly match find me and try my sons rifle out. You will not be disappointed.