If I were using the same case necked to either 30cal or 7mm (300 JAZZ vs 284 JAZZ) and looking for a hunting round to kill big white tail or even large caribou out to 1000 yards; which of the two would give me the best chances of a hit while still retaining lethal power. Now by "chances of a hit" I mean this, even a big magnum with a high BC bullet is dropping a foot for every 25 yards traveled....having a flatter trajectory helps compensate, to some degree, for those times when the range finder is off by a few yards. (maybe you can't get a reading on the deer, but you can get a reading on the big rock that he's walking in front of...but is he 5 yards in front of it or 10?) Also, wind..wind..and WIND. A 2mph full value wind can mean 12 inchs of drift, but a higher BC bullet and/or faster velocity could reduce that misjudgement to 10" (those extra 2" might mean the difference between a lethal hit and a wounding hit) I am just having a very hard time determining which caliber is superior when using the same case, I can calculate the drift and drop for various bullets. But its a game of guessing velocities. > > > a 180gr 30cal bullet will come out of the barrel faster than a 180gr 7mm bullet, but how much velocity difference will there be? And that is a simple comparison, it gets even harder to judge when comparing drift & drop of 160gr 7mm to a 200gr 30cal. And then there is the issue of terminal performance and bullet availability. Is it better to reach out with a 162gr A-max (7mm) that will impact with a few hundred fps more velocity but a few hundred ftlbs less energy than a 208gr A-max or is the advantage the other way around? And when you get into larger game, there is the 200gr Accubond with an SD of 301 and a BC of .588 ... but what does the 7mm have to compare to this? (bergers and a-maxs are much softer..correct?) and the 7mm accubonds max out at only 160gr with considerably lower SD and BC. Even with bullet construction and tougher animals left out of the equation, my head is still spinning as to which caliber bullet combination will produce the maximum ballistic advantage at 800+ yards. (Using the same case) Just a note: Please don’t throw .338 into the mix – I’m only thinking about 7mm or 30cal for this “light gun”.