I think I have read that the combloc produces heavy MG's in both 12.7 and 14.5mm chamberings. If so, why? Why not just one heavy MG like our own M2 fifty?
Thanks for any info.

The old ComBloc actually has a very unique array of calibers.  Most of their rew-served weapons can be found on this list:

http://www.fas.org/man/dod-101/sys/land/row/crewwpns_frame.htm

As for why they have two heavy machine guns, that is a good question.  Their 12.7mm round is 1cm longer than ours.  Their 14.5mm round is huge!  The 12.7mm is mostly anti-air and ground use, but the 14.5 is used a lot for anti-vehicle and anti-air use.  Both are impressive rounds.

Thanks cyoung!