05-24-2011, 05:30 PM
stanc Wrote:...If you're not going to compare candidate cartridges w/FMJ bullets to M80 and M855, might it be better to compare MatchKings (or Bergers, etc) in 5.56 and 7.62 to the new caliber? ...Good point -- the threshold is really trying to establish the weight and velocity needed for the caliber. Further, the M855 design means that using it to compare for this exercise defeats the principle of "like to like" bullet construction.
So, I've changed the master copy to read:
Threshold: Steel plate defeat
[INDENT]Perforate a 3.5 mm (10 gauge) steel plate at a lower velocity than with a 150 gr .308 bullet when using an open tip match bullet in both calibers.[/INDENT]
I also updated the rationale to indicate "The comparison can be made by establishing the V50 velocity for each caliber and bullet being considered."
Note that the range is deliberately left unstated, which opens the option for testing at ranges of a few tens of meters using reduced loads.