This is mainly for Meph.
I do not own it. However, everyone who I've talked to about it says it sucks. Basically, it gives the m4 two extra "modes" of shotgun fire. These "modes" do not equal to a supplementary cost of around 100k gralats (which is the cost of the gun + attachment). The two bullet and three bullet modes do nothing for the m4 user, except add freeze for the same amount of damage. It fires like the Lexel, in which all bullets hit, but only the base damage is given once.
With the attachment, the M4 should act like a special shotgun and add up damage like one, since the ROF is decreased with the rise of bullet count. It's very underpowered.