You don't have to do any mods what so ever to the front grip of the MR1 to put the Q-loader on. All you need is a ballpin hammer and some patience. You just take the largest ring and hammer it around the front grip snugly, and it works fine. The detent is a Timmy one... so it should be fine.
Here is a pic of how mine looks with no mods to the front grip:
