05-17-2011, 03:32 AM
LRRPF52 Wrote:...I would still like to see a muzzle velocity of at least 2800 fps versus 2600 fps for the LMG ammunition...I arrived at much the same conclusion from both intuitive and analytic arguments. The intuitive is based on where most of the classic full-power rifle loads are. The analytic shows that it one gets a good trajectory improvement going from 2600 to 2800 ft/sec and the added cartridge volume is much less than the change needed to go from 2800 to 3000. The trajectory improvement going from 2800 to 3000 is not particularly significant over the first few hundred meters.
LRRPF52 Wrote:...The most important things are reducing weight for the guns, and getting a lighter-recoiling cartridge, with a little gain in trajectory advantage. The calibers we're talking about seem capable of doing that right now, with FMJ's or acceptable mass-produced ammo per current guidelines...I gather from your earlier posts that a full-length (7.62X51 NATO COAL) cartridge is acceptable. Further, you ask that the bullet potential for penetration and perforation be at least that of the 7.62X51NATO M80 round. Most importantly, if I correctly interpreted yoiur comments, the lethality need only be intermediate between that of the 5.56 and 7.62 at all ranges.
6mm bullets can do this from surprisingly small cartridges.
We really do need to compare numbers against what we want the cartridge to do. Further, borrowing one of Stan's favorite refrains, we need to develop data to support or refute the analytic conclusions.
We can do the testing with reduced loads in .243 Win, .260 Rem, and 7mm-08 cartridges. That way we can avoid the added trouble and expense of wildcatting our favorite loudenboomer.
Cheers.