Does the 5.56 x 45mm round still have enough wallop downrange when fired from short barreled M4 carbines?

It is one of the reason the military is considering converting to 6.8 x45mm ammunition in a suggested M16 rifle - M4 Carbine Product Improvement Program. They are also looking hard at replacing the gas return tube with a spring loaded impriping operating rod.

The SR25 Sniper Rifle which recently adopted by the Army as its standard A sniper rifle is an AR-10 design, the 7.62mm weapon the M16 was scaled down from. A large number of M14 rifle have been reintroduced into the Table of Organization and Equipment (TOE) of many infantry units to provide for better long range fires.

The M43 7.62 x39mm Russian [Soviet] Ammunition does have more punch however the weapons that fire it such as the SKS, AK47 and AKM (et al) are better area fire weapons than point target weapon like the M16 series rifle or M4 carbine.

I think the M4 carbines are made for use in short range situations, like clearing rooms, urban operations etc.

Down range at 350-400 yards I don't think the the Ak is even effective. I know the M16A2 is fine at 500, yet the weapon is a little long for room to room engagements.

They would seem to be just as powerful, just not as acurate. I prefer the 7.62, especially out of a short barrel weapon. The 5.56 obvioulsly does not have the stopping power or damage potential as the 7.62.

Would you like to stand down range about 250 meters with a little white patch on your chest to find out?