LouBoyd pretty much sums it up. A subsonic 6.8 would be pretty weak. The kinetic energy of a bullet is given by the following equation:
KE=1/2mv^2;
Since the bullet is limited to subsonic velocities (~1080fps) the only way to increase energy is to increase the bullet weight. Thus you want to shoot the heaviest bullet that you can. The big attractions of the 300-221 Fireball (a.k.a. 300 Whisper) are:
1.) runs well in an AR15 platform and uses a standard Ar bolt/carrier and standard mags (including beta-c mags). You can not do this with a 338 Specter 458 Socom etc... )
http://www.quarterbore.net/forums/ph....php?photo=426)
2.) 240gr 30 cal bullets are readily available.
3.) The long heavy bullets seat deep into the case and limit the case to about 8-10 grains of powder. The load density is 90% or greater of the available case volume so the powder position is pretty constant. This give pretty constant subsonic velocities and pretty good accuracy.
4.) Long heavy bullets tend to be sub-critically stabilized, thus the readily start tumbling upon impact. A 240 gr Sierra bullet does not deform much if at all but tumbles soon after impact. Imagine a object ~1-5/8 in x 0.308 in tumbling through the target at about 900-1000 fps and think super broad head.
320pf
Hybrid Mode
