flattop - still not arguing either.
If you will compare 6.5 & 270 bullets with similar S Ds (sectional densities) you'll find the B Cs (ballistic coefficients) are awfully close. A few gun writers pointed out the accurate way to compare cals/cart.s yrs. ago.
Then with the heavier 270 bullets you'll have similar trajectories and BETTER wind bucking, & have more fpe, because they're heavier.
I am NOT trying to put down the 6.5s at all. It is not an equal comparison to base the comparison on bullet weight alone. That would amount to 'ballistic gack'.
The 260 & 6.5s are FINE hunting cartridges. They're just not as strong as some.
I find this to be categorically not true.
The SD of the 6.5mm bullets are as follows: 120g-0.246, 130g-0.266, 140g-0.287. The .270 bullets: 130g-0.242, 140g-0.261, 150g-0.279. The BCs of Berger bullets in 6.5mm: 130g-0.552, 140g-0.612. In .270: 130g-0.452, 140g-0.487, 150g-0.531.
So lets pick bullets of similar SDs to compare. Since a 120g hunting bullet from Berger is not available in 6.5mm, lets compare the 130g bullet in 6.5mm to the 140g bullet in .270. SDs are 0.266 vs 0.261 respectively.
On the Nosler website, the 6.5-06 lists a max velocity of 3058 fps with 23" barrel and a 130g bullet. The .270 Winchester max velocity with 140g bullet of 2910 fps with 24" barrel.
So using the BC information of both bullets at those starting velocities here are the ballistics according to JBM with a 100 yard zero and a 10 mph 90 degree cross wind.
300 yards the 130g 6.5mm bullet drops 10"/3.2MOA, drifts 4.8"/1.5MOA with energy of 1894 ft/lbs. The 140g .270 bullets drops 11.8"/3.7MOA, drifts 6"/1.9MOA with 1740 ft/lbs. At 600 yards, the 6.5mm bullet drops 66.9"/10.6MOA and drifts 21.3"/3.4MOA with 1282 ft/lbs, the .270 bullet drops 79"/12.6MOA and drifts 26.8"/4.3MOA with 1098 ft/lbs.
So the 6.5 mm have a higher BCs than the .270 bullets at similar SDs. They will drop/drift less and have higher retained ft/lbs than the .270 bullets started at similar velocities due to the higher BCs.
The data above shows that ballistically the 6.5-06 is a better chambering than the .270 Winchester.
Not sure the differences are enough to matter to anyone, but the data seems to argue directly with your post.
