Grendel LMG

[stanc]

OK, I see what you are getting at. We just have to demonstrate that we have an equivalent effective range, not equal terminal effects.

How do we define effective range? 50% hit probability was the U.S. Army definition assuming you had the ability to disable the target at that range.

Perhaps "effective range" was not the best term to use. What I'm thinking is that the trajectory should be at least as flat as for 7.62x54R.

The challenge will be to design a FMJ bullet with BC good enough to achieve that trajectory, when launched at a MV for which the cartridge is capable.

I think we'll have at least as good hit probability, but how do define disabling ability?

Good question. I don't know if there is a generally accepted definition.

Maybe it'd be best to just show gel tests comparing wound channels of 6.5 Grendel and 7.62x54R?

The old gel test of the Norma 120gr FMJ does look very similar to Fackler's wound profile of 7.62x54R. It's conceiveable that a FMJ bullet optimized for 6.5 Grendel could do significantly better than 7.62 at closer ranges. At long distances (over 400 meters), Gary Roberts says there's no real difference between different calibers.