From what Andrew has said about the .17 Aguila beating the .17 HM2 by 50-75 yds energy-wise despite the .17 HM2 having a 300 fps advantage, I think I've been able to calculate the 20-gr bullet's BC to ~0.200 or so to achieve these results. Andrew, if you could comment, is this anywhere close to being the case? I saw the picture you posted of the .17 Aguila round, and it indeed did look very long and streamlined for caliber. Still, that would be a BIG jump in BC for a .172 caliber bullet, as the heavier 25-gr Hornady HP is only ~0.185. Thanks.