I picked up a Tacstar saddle and immediately noticed that the forend was hitting the base when retracting the pump. A simple mod will take care of the problem. I've always been one for the quick and easy fix whenever possible. Here's a pic of my TacStar mod for reference...
All I had to do was drill a second hole 1/2" (center to center) inside the existing hole at the rear of the base plate. Drilling it slightly smaller than the others will eliminate the need for a nut to secure the screw. There is now plenty of room for clearance in the action using my aftermarket forend. The whole process took less than five minutes. I've fired several hundred rounds through this 590 and have had no movement in the TacStar at all...