6.5 Grendel—D.O.A.

[stanc]

Not feelin' like the author is informed. Totally new upper receiver? No, unless he's seeing the receiver and barrel as a unit?

Since in item 1 he talks about "a new AR-15 upper receiver is about 2/3s the cost of a new rifle," it seems pretty clear he's referring to a complete upper receiver/barrel assembly.

Difficult to mass-produce 30° shoulder? Maybe in the 1940s, as he cited. Lapua engineer Janne Pohjoispää's principal concern was mass production and minimizing wastage. I really don't think Lapua making high-end brass nor the Russian War Machine making 6.5 Grendel steel-case is particularly stymied by the 30-degree shoulder.

I don't know if he is right about manufacturing issues being the reason that the Army went from the original 30-degree shoulder to 20 degrees in development of 7.62 NATO. I was told (by Frankford Arsenal's last commander) that it was done to assure reliable chambering.

I'm skeptical that the Army would find the 30-degree shoulder acceptable. I can't think of any army that has ever adopted a rifle cartridge with a shoulder angle that steep. The steepest that I know of are 7.5x55 Swiss (28 degrees) and 6.5x55 Swedish (25 degrees). 5.56 NATO and 6.8 SPC are 23 degrees. Most military cartridges are 20 degrees or less. The USAMU's .264 USA is only 17.5 degrees, little more than half that of 6.5 Grendel.

New mags would "have to look significantly different"? Says who? He's just pulling stuff out of . . . thin air.

Disagree. Gene addressed this issue.

New development project for a 6.5mm M855A1 analog? Would cost millions? Uh, author didn't get the memo that Bill A. already did it?

I haven't seen Bill's 6.5mm EPR analog, so can't opine on whether or not the Army might find it satisfactory. Even if they did adopt Bill's design as is -- which seems highly unlikely, considering their history on such matters -- it would still be necessary to spend beaucoup bucks developing and testing 6.5mm Tracer, AP, Blank, and every other ammo type that the military uses.

Author wants an ironclad case for "increased and meaningful effectiveness and a tangible advantage in firepower for the squad." How about we start at something simple? Give me the "tangible advantage" of 7.62 NATO over 5.56 NATO. Not anecdotal theories, but quantifiable advantage. That should be simple, right? Quantify for us how much better at killing the 7.62 is vs. 5.56. If he can quantify something that has a more than 50-year history, then we will apply the same metrics to the 65G.

Few people advocate replacing 5.56mm with 7.62mm, so I don't see how that is relevant to the question of whether or not it'd be worthwhile replacing 5.56 NATO with 6.5 Grendel. I've said before that testing should be done to determine how much difference there would be in combat effectiveness with any proposed new caliber, rather than relying on calculated figures. So, I agree with the idea of finding out if there actually would be a "meaningful" increase in effectiveness before committing to such a switch.