[Buffalo Head]

So the Aussies have a bayonet that fits an M4 but we don't?

[archy]

So the Aussies have a bayonet that fits an M4 but we don't?

Nope. The Aussies use their F88 AusSteyers, which use the Eickhorn KCB-70 bayonet. The M4s are USMC M4 rifles with ACOG sights and the old issue M9 bayonet, now being replaced by the USMC by the OKC-3S bayonet, seen here on M16A2 rifles.