[Billthedrill]

...the firing system, which works under greater pressures created by the gases of detonating ammunition, puts more stress on moving parts, hurting its reliability.

Greater than what? It's the same ammo and the same action as its larger cousin. What are they talking about here?

[Dinsdale]

Gas tap not as far down the barrel perhaps?

[Noumenon]

Dunno - I'll stick with my FALs and NM Garand.

Call me old fashioned. Call the enemy out there at 400 yards dead.

[MindBender26]

the firing system, which works under greater pressures..

?????

With less barrel length, and thereby less time for gas pressure buildupm why not lower pressures????

Me thinks article author does not know XXXX from Shinola.

Had XM-177 (with bolt fwd assist) in RVN. Loved it.

[NMC EXP]

Same ammo + shorter barrel = higher pressure at the gas port
assuming the gas port is closer to the breech.

Regards

J.R.

[cpl tank]

The carbine gas port is located closer to the chamber than the gas port of the M4: 7.5 inches instead of the 13 inch distance on the M16. The gas pulse therefore enters the gas tube sooner and reaches the carrier group earlier than it does in the M16 length barrel. In addition to reaching the carrier sooner, it reaches it at higher pressure. The gas pressure at the carbine’s gas port is double that of the M16: 26,000 psi vs. 13,000 pounds per square inch.

[cpl tank]

The carbine gas port is located closer to the chamber than the gas port of the M16: 7.5 inches instead of the 13 inch distance on the M16. The gas pulse therefore enters the gas tube sooner and reaches the carrier group earlier than it does in the M16 length barrel. In addition to reaching the carrier sooner, it reaches it at higher pressure. The gas pressure at the carbine’s gas port is double that of the M16: 26,000 psi vs. 13,000 pounds per square inch.

[cpl tank]

mybad