Lee D.:
There are some subtle differences on paper and a couple that are not on paper that help explain the better penetration of the 6.5 compared with the .30-30. First of all, the listed energy for most commercial rounds in the 6.5 have in the neighborhood of 150-200 ft-lbs more energy than the .30-30. While these figures are theoretical, they do reflect the comparative physics involved. That's not a huge difference, but enough to notice on game.
Secondly, it must be remembered that the bullet diameter is markedly different, and thus the way energy is expended will also differ accordingly. The relatively fat, short, and thick .30-30 bullet will spread its energy out more laterally upon impact, whereas the relatively long, narrow 6.5 bullet will tend to penetrate farther and spread energy more horizontally in the direction of the bullet path. This creates the better penetration and in many cases the deeper destructive effect of the 6.5.
Lastly, it should be noted that although energy is similar, bullet velocity is quite a bit faster in the 6.5, which, coupled with the much greater sectional density of the bullet explained above, also contributes to both the penetrating ability and destructive shock value of the 6.5 in an adequately expanding bullet.
One of the reasons I settled on the 6.5 was because it seemed to offer the best compromise between the high velocity school of thought and the big bore school of thought; a medium-diameter big-game cartridge with enough velocity to perform well on most medium to large game animals. All this without the excessive blast and kick of the overkill magnums and long-action calibers. So far it has proven very effective. :grin:
