handirifle -
I’ve often thought it more appropriate to consider bullets of similar sectional density when comparing different calibers. If we were to do that with the 7mm Rem Mag and .30-06, we would compare a 140g 7mm and a 165g .308” bullet. I also think it best to zero for a Maximum Point Blank Range for a defined target (kill zone) size. I tend to be fairly conservative on the target size and use a 6” diameter – meaning that for Maximum point Blank Range the bullet will never be more than 3” above or below line of sight.
Given those parameters, a 7mm Rem Mag will drive a 140g Partition to 3340fps, according to Nosler 5th, for a MPBR of 327 yards. At 400 it is down only 9.9”, doing 2495fps, and carries 1935fpe.
Contrast that to a .30-06 which will drive a 165g Partition to 2940fps for a MPBR of 290 yards. At 400 yards it is down 16.6”, is doing 2122fps and carries 1649fpe.
If you insist on comparing bullets of similar weight, Nosler 5th says a 7mm Rem Mag can drive a 160g bullet to 3112fps for a MPBR of 209 yards. At 400 yards the bullet is down 12.4”, is doing 2370fps and carries 1996fpe.
Hitting the target is one thing, hitting it effectively is quite another – there is a reason I won’t hunt elk with 130g bullets in my .30-30, even though they shoot fairly flat. Given the loads cited above, the 7mm Rem Mag delivers up to 350fpe more at 400 yards than a .30-06. Although both trajectories are manageable, I prefer the extra energy the 7mm Rem Mag provides.
Let’s assume a hunter is not willing to shoot past his MPBR – or 290 yards with the 165g .30-06 load and 327 yards with a 140g 7mm Rem Mag load. With the 7mm Rem Mag he covers an additional 19, 820 square yards, roughly the area of 3.7 football fields.
Don’t think MPBR is a reasonable maximum range and want to use something else like a drop of 10” to determine maximum range? Fine. The 7mm Rem Mag range will be 405 yards (-10.1”) with the 140g bullet and 385 yards (-10.5”) with the 160g bullet. The .30-06 range will be 355 yards with the 165g bullet. In this case the 7mm Mag allows the hunter to cover the equivalent of an additional 7.1 football fields with the 140g bullet and an additional 4.2 football fields with the 7mm Rem Mag 160g bullet.
No one I know chooses the 7mm Rem Mag because they think the .30-06 is inadequate at short ranges – they do so because the 7mm Rem Mag provides an advantage when the ranges get long.
Not knocking the .30-06 (which would be kind of stupid since I shoot a .308 Win as well as my 7mm Rem Mag), just trying to point out the differences when using optimum loads.