User blog comment:Arbington/ME3 Theories/@comment-899316-20100804050030

A mass accelerator cannon would be good, but it would be really inconvenient mounting them on all the ships. I'm assuming these are akin to the MAC cannons in Halo, which are essentially kilometer long coil-guns. Most ships in Mass Effect are too small to have a Halo style MAC gun installed, but maybe they're smaller in the Mass Effect universe.