Universal Ammunition: Not quite universal, but so far as regular guns go (see Bottomless Magazines for the description), there are very few different types of standard magazine cartridges (metal for slicing up), powercells (which are just the fast-discharge versions of regular battery equivalents), and heat sinks which cover virtually everything on the market. And even where slugguns are concerned, there aren’t all that many different bore sizes beyond the two main ones, and the rest of the compatibility issues can often be handled by software patch.
Conventionally averted where the exotica are concerned, though.
So the Empire basically uses the same guns as the Mass Effect universe?
In many ways, yes, technological-base-differences notwithstanding, except for the slugguns, and with much more software support.
The chief difference in the similarities, as it were, being that while the ME universe switched from internal-heat-sink-and-dispersal-only to thermal-clip-only, Eldraeverse weapon designers figured that the latter made a good supplement for the unreasonably powerful and/or high-firing-rate weapons that would otherwise run out of capacity but that there was obviously no sense in taking the former out. A weapon whose firing rate is heavily capped being still better than a weapon that won’t fire at all, belike.
Yeah, the shift seemed kind of contrived. Too many fans wanted a more familiar “ammo” system I guess.