Optimized Caliber

[JASmith]

I think that to have one cartridge in two versions, differing only in the length of the bullet protrusion and the chamber pressure, would be confusing. We don't want to get into a 6.8mm Rem situation, with two different chambers! ...

I understand the logic, but there is also the logic of the enormous investment needed to qualify a new cartridge. The 6.8 and the Grendel have both gone through the process. The Grendel even has steel cases in the pipeline.

I've done the math, and adding, say .05" to the body length adds only a grain or two to the case capacity. This is somewhat less than the 3+ grains one gets by merely seating a COAL of 2.4" to 2.5" with no other change to the cartridge. The case remains the same.

I've also looked at scaled drawings of the longer case -- there won't be any confusion between the two because one will have a conventional appearance and the other will have the tip of the bullet sticking waay out there!

Having said the above, I would concur that, should the investment be available (a truly huge IF!), then the most attractive options would boil down to lengthened versions of either the 6.8 or the Grendel, both in 6.5 caliber.

The fatter case of the Grendel-based option would likely be more weight efficient because the wall thicknesses tend to remain about the same, so the case weight in that area goes with the radius, while the volume of the interior goes with the square of the radius.