: Assuming the "Imperialist
: forces" weren't human or had better technology that hadn't been
: shared or whatever.
They were human, this was some 350 years before the Marathon is attacked. The way Durandal says it, it sounds more like a specialty weapon or experimental weapon than a strong line of technological development. If it was such a successful design, why wasn't it replicated or at least retained? It seems that the WSTE-M was pretty well forgotten about by the time the Marathon was attacked.
I thin it's more likely that Durandal found the reference to a bulky, poorly designed double-barrelled shotgun and thought that a cyborg like you could probably use it. Even if it uses the teleportation of magic, it would still be nearly impossible for a normal person to weild with any accuracy, hence it faded into history...
: But, for theories sake, consider "Hammer Space" a scientific
: anomoly that wasn't proven until the WSTE-M5 shotgun was created. ;)