Well, I own Magnums, and I own non-magnums, and as far as I'm concerned, the magnum has an advantage only in fairly specialized circumstances. The Magnum does shoot somewhat flatter than it's standard counterpart, but not as much as some seem to believe. The magnums also arrive at distant targets with a bit more oomph. An interesting fact is that some factory loaded Magnums are a bit on the "soft" side, velocity wise. Death-Junky mentioned the "tremendous" difference between the 7mm Mag and the 300 Win Mag. 
FWIW, The 175 grain 7mm has better sectional density than does a 30 cal 180 bullet, so if construction is similar, the penetration advantage lies with the 7mm. I will share an interesting revelation to those who care to listen. I took some factory ammo to chronograph for a couple of friends who wanted to know what the factory ammo was doing in their guns. One rifle was a 300 Win Mag, a Krico [fine rifle, and very accurate], the other a 30-06, a 22" barrelled M70 Winchester.[also quite accurate] To avoid reflecting negatively on any manufacturer, I will refrain from saying what ammo was used. Suffice to say that in both cases, it was popular, factory ammo loaded with 180 grain PSP type bullets, not any light magnum stuff. Imagine our surprise to find the 30-06 ammo clocking 2756 fps average for 5 shots across the chronograph. Pretty impressive for the old warrior! Also imagine our chagrin to find the 300 Win Mag doing 2822 avg for 5. Quite wimpy for a 300 Mag, and certainly not enough difference between those two loads to give any practical advantage to the 300. I know, I know. If you handload, the 300 Win has a 300+ ft second advantage over the '06. I don't want anyone sending me a three page, single spaced letter lecturing me on my lack of acuity on these facts! But what I'm saying is that sometimes we see some guy in the field with his magnum, imagining he is packing the hammer of Thor, when in fact, if he is using factory ammo, he may be in the same category as his partner packing the non-magnum. I have seen similar scenarios between the 7mm Rem Mag and the 280 Remington using 175 grain bullets. Some factory ammo is up to snuff, of course, but you'll never know for sure unless you either chronograph it or shoot it out to 4 or 500 yards on paper to calculate actual drop. If you know your magnum's velocity is at it's true potential, and you have a need for the extra power and subsequent flatter trajectory, go for it, but the majority of hunters would not be seriously handicapped if they shot standard chamberings and got to know them well. Regards, Eagleye.
FWIW, The 175 grain 7mm has better sectional density than does a 30 cal 180 bullet, so if construction is similar, the penetration advantage lies with the 7mm. I will share an interesting revelation to those who care to listen. I took some factory ammo to chronograph for a couple of friends who wanted to know what the factory ammo was doing in their guns. One rifle was a 300 Win Mag, a Krico [fine rifle, and very accurate], the other a 30-06, a 22" barrelled M70 Winchester.[also quite accurate] To avoid reflecting negatively on any manufacturer, I will refrain from saying what ammo was used. Suffice to say that in both cases, it was popular, factory ammo loaded with 180 grain PSP type bullets, not any light magnum stuff. Imagine our surprise to find the 30-06 ammo clocking 2756 fps average for 5 shots across the chronograph. Pretty impressive for the old warrior! Also imagine our chagrin to find the 300 Win Mag doing 2822 avg for 5. Quite wimpy for a 300 Mag, and certainly not enough difference between those two loads to give any practical advantage to the 300. I know, I know. If you handload, the 300 Win has a 300+ ft second advantage over the '06. I don't want anyone sending me a three page, single spaced letter lecturing me on my lack of acuity on these facts! But what I'm saying is that sometimes we see some guy in the field with his magnum, imagining he is packing the hammer of Thor, when in fact, if he is using factory ammo, he may be in the same category as his partner packing the non-magnum. I have seen similar scenarios between the 7mm Rem Mag and the 280 Remington using 175 grain bullets. Some factory ammo is up to snuff, of course, but you'll never know for sure unless you either chronograph it or shoot it out to 4 or 500 yards on paper to calculate actual drop. If you know your magnum's velocity is at it's true potential, and you have a need for the extra power and subsequent flatter trajectory, go for it, but the majority of hunters would not be seriously handicapped if they shot standard chamberings and got to know them well. Regards, Eagleye.
