Optimum 6.5 Grendel bullet weights

[JASmith]

Well, if you consider clothing as a significant barrier to rifle bullets, then yes, that "barrier" test should be done. I rather doubt that the performance of a TSX (no matter what weight or caliber) will be noticeably different than the same bullet against bare gel.

The only other barrier likely to be encountered in CQB (against the current enemy, for which the TSX "brown tip" load was created) is a loaded AK mag in a chest pouch. Body armor isn't likely to be worn.

True, but just how much penetration depth do you think is necessary? I've seen nothing to indicate that an 85gr TSX wouldn't have more than enough. The wound cavity of the 120gr 6.5 TSX is substantially inferior to that of the 85gr 6.8 TSX, and the 22+ inches of penetration depth is far more than needed. Or are you planning to get two opponents with one shot?

I'll rephrase the last question in my previous post: Why do you "almost certainly want to at least match, if not exceed, the sectional density of that [70gr 5.56 TSX] bullet"? Is there something vital about that SD?

There is a reason a heavy copper alloy bullet was selected for the CQB mission. The sectional density and ruggedness of this bullet compared to other choices available tell us that penetration is a significant issue.

Even today, CQB frequently involves impromptu barriers, vehicles, buildings, etc.

Advocates of the Grendel, or any other cartridge, must look beyond the current conflict. The one certain thing is that at least some of our adversaries will adopt body armor.

My understanding of the issues, based on a long association with the weapons R&D community, is that these seemingly unreasonable requirements will be imposed on new acquisitions.

Of course we know that every one of us, including me, will get the issues wrong on at least one point. The challenge is getting a read on what the requirements will be.

One could track the Commerce Business Daily for RFP announcements in this area. There is a possibility that a request for proposal will be released. If we are lucky, we could get an unclassified public release approved requirements document by responding.