I am probably way overthinking this as either choice will likely work fine but figured I would get some opinions anyway. So I have an AR-15 in 350 Legend that I am going to hunt deer with this fall. I have bought the Federal ammo for it instead of Winchester ammo. I have the 180 grain soft point Power Shock and have some of the 160 grain Fusion rounds. I originally got the 180 grain bullets after reading an article talking about sectional density needing to be over .200 for decent penetration. The 180s barely make it and the lighter bullets in 350 Legend are under that. So in my mind, I picked the 180s thinking I will get the most penetration ensuring an exit wound and decent blood trail. Another article also mentioned the sectional density figure of .200 being acceptable but also added the caveat of "bullet design and construction being equal". This led me to look at the 160 grain Fusion rounds as their jacket being bonded to the core should be an advantage in penetration over the 180 grain Power Point where the jacket is not bonded to the core. Also, the 160s are 200 fps faster at the muzzle, shoot flatter, and carry more energy to the target (at least out to 300 yards) than the 180s. But their sectional density is less than the often cited .200 for deer. I have not shot both of these head to head yet to see which one shoots better groups but assuming they shoot equal groups, do I go with the round that shoots flatter and hits with more energy and has a bonded jacket/core or do I go with the heavier bullet with better sectional density that meets the commonly accepted minimum density but doesn't have the jacket and core bonded together and hits with slightly less energy and has slightly more drop? Like I said, either one will likely kill whitetails cleanly out to 200 yards and in reality most of my shots will be under 100 yards. So I don't think there is a true wrong answer here. Just curious as to what others would choose between the two given the information above.