Exotic 1911's do not grant weapon XP
So I found an exotic case with the pistol in it, ran through a match and enjoyed the explosive bullets and ended the game with the gun still lvl 7 from use in Multiplayer. So I ran through and farmed up a few more exotic cases and found another weapon, swapped out the cursed 1911 for a swordfish and later found a new 1911 untouched by the exotic weapon bench. Still no weapon XP.
So I thought, okay I'll find another exotic I don't have to 250. I found a EGRT-17 called 'Collateral' - used it and the weapon leveled up to 20. So now I'm wondering if anyone else has had this issue. Is is because of the 1911's explosive bullets somehow? Doesn't effect the XP gain of the snipers I know that much.