The M26 Mass, or M26 Dart is a glitched weapon that people are rapidly exploiting. That being said, a lot of the previous weapons were glitched as well and were exploited just as equally. This one, however, is a bit more complicated in it’s use.
The G3A3 is the main weapon. This is about the strongest Assault rifle in the game, and combined with the heavy barrel it packs quite a punch. The undersling can be used on certain rifles like the G3A3 and this will benefit the M320 and the M26 by mounting these weapons on to the gun. When using the G3A3 with the undersling and heavy barrel, the M26 gets it’s power from the G3A3’s bullets, making every shot with the M26 instant death, and from quite a long range.
Being a so called “glitched” weapon, this set up of the M26 will get you kicked or banned from a lot of rented servers. While rented servers are not allowed to restrict weapon use, the server ToS gives them the right to kick you for using this glitch.
While I don’t want to encourage people to use it and get kicked/banned from servers. As fun as this weapon is, it IS a noob gun. But that being said, if you are looking to unlock all your mastery dog tags, I would find some non restricted servers and get your kills before it’s nerfed useless, and receive plenty hate mail in the process.