Grendel LMG

[stanc]

An LMG will have a much larger bolt, and won't be limited by AR mag-length COAL. Basically, you're looking at bolt gun velocity potential, and my friend is getting 2650-2700 fps with 139gr Lapua Scenars out of his Cz527 Grendel, so a 130gr at 2650 should be quite doable.

Loaded to longer than AR mag length, and to substantially higher than AR pressure? Perhaps.

Although since it's standard practice to have rifles and LMGs in the same caliber, that would rule out conversion of 5.56x45 and 7.62x39 rifles, necessitating development and acquisition of new rifles.

Another point to consider in advocating a 130gr projectile: for the US and NATO, it will need "green" construction (steel tip and copper slug, most likely), while the V4 and Russia would doubtless continue to use steel core. For both, a 130gr bullet would be very long for caliber, longer than the Hornady 120gr GMX (1.4").

Would that present stability problems?

Would it permit a matching Tracer bullet? (Tracers are typically longer than Ball rounds.)