ORIGINAL: Paul L Mohr
I think you are confusing bullet weight with bullet design. A heavier bullet in the same caliber and design will give you better momentum for increased penitration and a better ballistics coeficient because it will be longer with the same diameter.
Paul
Our present domestic standard load for the 6.5x55 mm Swede is a 139-gr. or 140-gr. pointed soft-point bullet driven to 2550 fsp.s. muzzle velocity. Although those bullets still retain a high sectional density of about
.289, comparable to that of the 160-gr. 7 mm
(.283) and 190-gr. .30-cal.
(.286), and tend to penetrate well, nowadays the cartridge is recommended only for deer and similar size game. The potential of the 6.5x55 mm is limited by its maximum working chamber pressure being restricted to
46,000 c.u.p. (copper units of pressure), compared to 52,000 c.u.p. for many more modern rounds.