I attended the jungle warfare sniper course in panama canal zone back in the 1970s before the army sniper school at ft benning was developed, we shot 3x9x40 with standard crosshairs, and learned hold over and how to judge wind, and I have no problems hitting 1 gallon milk jugs with a 3x9x40 out to 500 yds now, with my old eyes, the trick to shooting is to know where your bullet is at any given range and accommodate for that drop and windage.
a 30-30 is a very capable deer round out to 300 yds. if you know what you are doing, 3 weeks ago my nephew came to the farm to sight in his deer rifles, a 30-30 Rossi 94 clone, and a 243 t.c. he was shooting the 30-30 at 50 yds with standard buckhorn sights, his 243 T.C. had a 6x18 Nikon prostaff on it, after zeroing at 100 yds I asked him to swing around to the 300 yd steel swinger I had in the field, he stated that he did not think it could be done, I had him hold at 12 oclock on the 18" square target and he was hitting 7 inches low right where I thought it would.
them I asked him to use the 30-30 carbine, and he stated that no one could hit that target with a 30-30 at that range, so I asked him to hand me the Rossi, and three rounds and with me shooting offhand while sitting on the range table I showed him it was very doable, he stated that he would not have believed it if he had not seen it, and then he stated that the 243 hit the steel harder than the 30-30 and I explained that the 100 grain 243 was delivering over 1000 lbs of energy at that range, while the 150gr 30-30 was only delivering 640 lbs of energy at 300 yds., and that was 50% more energy than a 230 gr. 45acp was delivering at the muzzle.
so don't underestimate the old 30-30 round, it more than a 50yd brush gun