Dr. Marneaus
.270 WIN
and also, people dont understand that Shockwave Technologies got clarification from BATFE on this back in 2010, and it technically has ALWAYS been legal to build yourself one of these assuming you started with a PGO firearm.
How can it be legal to build one, but not legal to modify a factory built one? LOL
How can it be legal to build one, but not legal to modify a factory built one? LOL