5.56 replacement: 6mm-class cartridges vs high-pressure smaller rounds

Key points: 5 56 replacement 6mm-class

• His baseline is that nothing replaces 5.56 soon: high-pressure 5.56 and the HICAR program show the cartridge still has headroom, so this is speculation about a change that may be decades out.
• Path one is more capability: routine 300 to 500 meter engagements with better terminal performance from a larger caliber, most plausibly a 6mm-class round such as 6.5 Creedmoor or 6mm ARC, picked for high BC and load versatility.
• That path depends on small-frame AR-10s becoming as reliable and light as an AR-15; he cites LMT's 14.5-inch 6.5 Creedmoor MRGG as a precursor that is still too heavy to be standard issue.
• He doubts it anyway: infantry exists to take and hold ground, mostly inside 200 meters, while longer range belongs to drones, artillery and specialist marksmen, so the added weight could cut effectiveness.
• Path two is less weight and more ammo: high-pressure 5.56 already lets a shorter barrel match 14.5-inch performance, and he floats the same concept applied to a smaller cartridge that could meet current 5.56 standards.
• Any replacement must keep current range and terminal performance while delivering a significant gain in ammo carried or weight saved, including supply-chain weight, and he expects physics to cap how much velocity can make up for a lighter bullet.
• Allied interoperability, the same hurdle facing the NGSW program, guarantees that any eventual replacement of 5.56 will be slow.

About this Ballistics Focu video

5.56 replacement, argued from the infantry's job outward: Boondock Ballistician says nothing displaces 5.56 soon, then sketches two paths for the decades ahead. One trades weight for reach with a 6mm-class cartridge in a small-frame AR-10, foreshadowed by LMT's 14.5-inch 6.5 Creedmoor MRGG, which he doubts suits troops who fight mostly inside 200 meters. The other follows high-pressure 5.56 toward less weight and more ammo, possibly through a smaller high-pressure cartridge, if it can hold current range and terminal standards.

Transcript: 5 56 replacement