07-09-2013, 11:10 PM
cory Wrote:...Could the BC and charge of the Tracer round not be adjusted to match the trajectory of the 130gr FMJ or at least to the tolerance of the current 556 tracer round to the M855A1?Frankly, this looks like an idea worth pursuing. I will admit that it hadn't occurred to me.
Implementing might be a challenge, but probably doable if we don't ask for the best possible BC for the FMJ and are willing to allow a bit more manufacturing cost for the tracer to keep its BC higher. That trick, combined with carefully crafted specs for harmonizing the tracks, might lead to an interesting tracer & ball combo for the Grendel.
I am not convinced that one must go with a 130 gr 6.5 caliber projectile to have a credible replacement for the 7.62 M80 round. Take a look at the Norma 120 gr FMJ. That bullet with a BC of .428 should have comparable barrier defeat capability to the M80 at all ranges when launched at a muzzle velocity of 2600 - 2650 ft/sec. This assumes the M80 has a barrel length of 20 inches. Furthermore, we get an idea of how well that bullet can transform into a steel-core version by looking at the Barnes TSX (BC .381), the Barnes TTSX (BC .412) and the Hornady 120 gr GMX (BC .450). Any of those shapes should have enough velocity at long range to have barrier defeat potential consistent with that of the M80.
Further, the variation in BC tells us that we could indeed harmonize the FMJ and tracer even if the tracer weighs somewhat less to accommodate the trace element.
Wounding potential is another question, but I can flatly state that kinetic energy is inappropriate and misleading metric for wounding potential.