Military round comparisons

[Trooper]

(Tony Williams - who else?)

Absolutely right, Stan. Thank you for pointing that out. And the SF community is seriously interested in a weapon in a calibre that can deliver the associated benefits.

The Canadian paper study presented at Shrivenham last year showed just how effective the Grendel could be - when fired from a weapon with a 24" barrel. It has done much to re-ignite the calibre debate in military circles.

However, as soon as you fire the existing 6.5 Grendel from a weapon with a 16" barrel, retained energy levels drop-off alarmingly - to the point where the Grendel offers no appreciable difference versus 5.56 mm. This has been tested and validated by at least two mainstream manufacturers. (It may also explain why Dr. Gary Roberts gel tests were inconclusive). Hence my view that a slightly longer cartridge with increased powder capacity would easily overcome the problem and provide a true GPC round.

One of the other things I've been looking at is whether an extended version of the 6.8 mm Remington SPC case would be a better alternative to an extended Grendel case. While it would create a longer, more slender round, as LRRPF52 points out, the Grendel case can take more pressure. So, the 39 mm 11.3 mm case is the right one to extend IMO.

I like everything about the Grendel round except case length. A long case with a less pronounced shoulder would also facilitate easier feeding.

When comparing to the 7.62x51 NATO, remember that it was designed for a 20" barrel (M14 or the FN FAL), not for a 16" as we have on the M4. Thus comparisons need to be with 20" barrel platforms. Thus how does the 7.62 NATO fired from a FAL or M14 compare to the 6.5mm Grendel fired from an M16 (AR15) having an 18" or 20" barrel? Even the M60 MG or the M240 MG use longer barrels.

The shorter M4 barrel would not be a good comparison. Even the 7.62 NATO does not perform well out of a 16.5" barrel. But then that is not why we use the shorter barrels. One should not expect good performance out of a shorter barrel. The shorter barrel is for close quarters work. If we want .308 performance then we use a 20" barrel for the 6.5mm Grendel.