JASmith Wrote:The focus on 7.62 replacement relaxes both the length and the body diameter constraints a bit.Disagree. To paraphrase Tony, if a cartridge is too close in bulk and weight to 7.62 NATO, then it won't be worth changing. Diameter of 0.44" and length of 2.8" is, IMO, much too close to the 0.47" / 2.8" of 7.62x51.
I don't remember off-hand if the explorations in Military Guns & Ammunition looked at a 0.445" diameter body and a COAL of 2.81" but a cartridge meeting these constraints might be the best shot at an attractive 7.62 replacement for dismounted infantry.
Quote:How much a caliber improves the soldier's ability to hit in this family of cartridges will likely be the deciding factor.Disagree. All of the intermediate cartridges proposed to replace 7.62x51 can be expected -- if only because of reduced recoil -- to improve hit probability over that of the 7.62 NATO round.
IMO, the deciding factor is probably more psychological: how close to 7.62 terminal effectiveness does the alternative round deliver. If a new cartridge doesn't get close enough to 7.62 in "punching power," it won't have emotional appeal.
Remember, rounds like 6.5 Grendel and 6.8 SPC were aimed at replacing 5.56 NATO, to improve performance of the carbine and rifle. The concept being discussed now is intended to replace 7.62 NATO, to reduce the ammo weight of the GPMG and DMR.