I just ordered some of these. I plan to use the .224 60 gr. MK's against rodents with my 7.7 twist .22-.250's, 26 inch barrels. Planned powders include on-hand H414, CFE 223, IMR 8208. The Hodgdon data gives velocities above 3,500 fps with 60's at about 61K psi with these powders. CCI 200's will be used. I called the Sierra folks and they gave me a thumbs up for my plans. The OAL for the 60 .224 Tipped MK is .910. My Miller Sg, calculator modified for plastic tips, comes up with 2.8 (3500 fps, 85 degrees). On closing the Sierra guy said, "have fun". Any other members using something like this combo with 60 gr .224 MK's? I normally use Hornady's but they don't have a zippy 60 gr. expanding, pointy boat tail bullet. I want to flatten trajectories and get more expansion than 68's & 75's. Max ranges will be 500-600 yards. My 7.7 twist rifles are just OK with the much shorter 53 VMax bullets.