Don:
I thought the M203 combination was an M16A2 with a M203 grenade launcher?
I also thought it DID fire 5.56...
The way it was explained to me, the M16 was more reliable, accurate and easier to deny if left behind...
Either way, I have no knowledge of any L1a1s at Hereford, I know the SEALs kept some M14s to give them more firepower in a scrap....
Poccur