I recently replaced the foregrip on my Mossberg 590 with a pistol grip. Since then, I've noticed that the action slide seems to have more play in it than I'd like. This was somewhat noticeable with my old foregrip but it is much more noticeable with the new. I've also seen this on my model 500 20 gauge. It seems to be inherent in the way the twin guide bars are attached to the slide. Does anyone have any suggestions for tightening this up?