I quit using pumps because of the forearm rattle and the wobble. The mechanics of the action has to have a certain amount of this built in. Seems some rifles are worse than others, even among the same brands. There was a forearm modification I saw done to a pump rifle by a gunsmith for a hunting buddy in the 1960s. He epoxied two nylon buildups on each side of the forearm, not directly across from each other to prohibit binding. They were also placed forward enough that they did not ride over where the barrel swells appreciably by the breach. They were little lumps about dime size at the base and about the size of a small nail tack head where they contacted the barrel. He oversized them and then sanded them down so there was no binding. It did not remove all the wobble, but the rattle was greatly reduced and the wobble also somewhat reduced. Being nylon, they almost acted like rattle shock absorbers. They also reduced the side to side wobble somewhat, so this also reduced the rattle.
