Now as far as trajectory and theorys. thats just it its theorys. I have successfully shot steel plates at 100 yrds easy, 200 yrds ok, 300 yrds, my son can do i cant consitantly.
I gotta be a bit of a nay sayer (I still like the .30-30) on that one. Trajectories aren't theory, they're real. My PBR for my .308 is 273 yards. That means to almost 300 yards, I just hold the crosshairs on the shoulder and squeeze, 300 a little high on the shoulder. The .30-30 cannot do that. My little .308 is has shot a 3/4" 5 shot group, though more often than not it's more like 1 MOA. Now, my Savage 340 would do that even with cheap factory ammo, but most lever guns won't. That's not trajectory, though, that's accuracy. But, for long range shooting, if you live west of the Balcones Escarpment in Texas, you might think about moving out of .30-30 land. However, if you have an accurate one, the new leverlution gives the old round a little more equity.
Another thing to consider with long range shooting on game is energy. No, it's not theory either, it's real. The .308 is pushing 1400 ft lbs at a full 400 yards. My .30-30 shoots the same nosler 150 grain bullet as my .308. Okay, it's out of a 12" barrel, so give a cuple hundred more ft lbs for a rifle, but it starts out at 2050 fps 1308 ft lbs AT THE MUZZLE. It drops below 1000 ft lbs (the mythical minimum for deer) by 200 yards.
So long as the range is under 200 yards, the deer really doesn't know the difference, honest. But, lets don't get too carried away, here, LOL! If I need more than PERHAPS (with leverlution) 300 yards range on deer, more like 250 really, I'll pick something else. I very rarely need more, though. That's the catch.
It's only when I travel west that I feel the need for more and even then I could get by with the .30-30 I think, with the new leverlution. I've seen folks hunting in New Mexico with nothing more than an iron sighted 94. It can still be done, just gotta pass on shots a little before you would with your .300 mag or .30-06.