Seems like most armies are adopting, or have adopted, 120mm recently in preference to 81mm. Longer range, three times the HE on target, lots of gucci PGM type stuff that we wont buy... I can't even see the logistics being a huge problem with the US using it in theatre. Even if the ammo ran out you can still use 81mm ammo in them with an attachment. The tubes might be technically less mobile than 81mm tubes but the FOBs don't move, might even free up the smaller tubes for patrols etc. Cheap and effective?