FMJ yaw and upset performance

[LR1955]

I am interesting in promoting the idea of a long-range intermediate military cartridge capable of replacing both 5.56mm and 7.62mm NATO rounds.

In order to be "Geneva legal" without getting into lots of arguments with lawyers, the bullet needs to be of the FMJ, non-fragmenting type - definitely not with an open tip. The wounding mechanism will therefore mainly be via rapid and reliable yaw and upset on impact: the bullet should start to yaw within about two inches of entering a body, and should have entirely turned over and be travelling backwards by about 12 inches.

The problem is, I have read in a British report that in a gel test by Alexander Arms of an FMJ bullet fired from a Grendel case, it did not start to yaw until after penetrating several inches, which is not good enough.

So I really have a two-part question here:

1. Is it possible to design a low-drag 6.5mm FMJ bullet of around 120-125 grains which exhibits rapid and reliable yaw and upset on impact?

2. Is it possible to achieve the same performance using a lead-free bullet, since that seems to be a growing military requirement?

Tony:

In answer to your questions. I am sure both are possible. I am also sure the same can be done with 5.56 and 7.62 at a much lower cost. And I am also sure that what ever design got developed that it would not increase battlefield lethality.

For the lead free designs, that too is possible. The same is possible with 5.56 and 7.62.

Same goes for designing something that starts to yaw in two inches. Am sure it can be done given enough money. The result would probably be dollar a shot ball ammo whose hit probability is less than a similar redesigned 5.56 and 7.62 because anything it hits on the way would result in it becoming grossly unstable.

Still haven't commented on some new VLD design ball round out shooting surface danger zones on ranges. Or the basic weakness of the Grendel bolt and the lack of reliable magazines.

LR1955