Trooper Wrote:With the infantry rifle being 16", the assumption is that engagements would be 300 m or less to include CQB inside buildings. The shorter barrel (carbine or bullpup) would not be designed for longer range engagements. A certain level of performance degradation would be assumed.
I do think that the Grendel cartridge might do better if longer. How much could it be increased and yet fit within the dimensions of an M16 magazine well? There is advantages of using the current platform (M16/M4) with new barrels to ease costs thus a gradual transition. But if it is determined that we need a longer case, how much longer? I do think that the diameter of the Grendel should stay the same. What is the smallest case that can still perform as well as the .308 caliber (7.62x51)? And should we want a heavier bullet, and how much? Should we aim at 140 gn?
Here we go again....
How to make a Grendel cartridge longer but not wider that still fits within the limitations of a AR-15 Magazine? Eliminate the shoulder or neck. Since that won't work, you have hit your limits.
You want something that will outperform the military versions of the 7.62 but still retain the Grendel case? Neck the Grendel down to 6mm and shoot 6mm bullets. Will that ever be done? No.
I can imagine the need for a quadrant sight if someone wants to shoot a ball 140 grain bullet from a 16" barrel Grendel. A 140 is too long and too heavy for the cartridge capability. In other words, a 140 using current materials is a horribly inefficient bullet to shoot using a 30 grain cartridge that is restricted by magazine length. Not to mention pressures. Sure, guys shoot the 140s. And they have to hot load them to dangerous levels just to get early 20th century velocities out of them.
The facts are that unless something radical changes in terms of propellent or bullet material, you won't get the increases in lethality that would justify billions of dollars being spent on something new. It isn't even logistics. It is money and money that is better spent on things other than trying to improve early 20th century technology that has already hit a 97% capability if not more.
LR1955