Originally Posted by vafish
I have 3 Mossberg 500's and 1 Remington 870.
The 2 newer Mossberg's have very little rattle to the fore end. The older one the fore end rattles around the mag tube quite a bit. I bought it used and have no idea how many rounds have been fired through it. It was fairly abused looking when I got it. After some sand blasting and Duracoat it looks great.
The 870 rattles a little bit as well. I've had it since the mid 1980's and it has been shot quite a bit.
If the fore end rattle bothers you then get the 870, but it really has no effect whatsoever on the function of the 500. The 870 will eventually start to rattle a bit too on the fore end.
The rattle on the 500 is mostly due to the design of the action bars and the amount of space between the fore end tube and the magazine tube. The action bars on the 500 are separate pieces pinned to the fore end tube and can move independently. This helps eliminate binding in the action of the fore end is twisted. The Remington 870 action bars are welded to the fore end tube and do not move.
I own 2 Mossberg 500s and the rattle has never bothered me either, it kinda amplifies the "shuck - shuck" sound we like.
Sounds like your sales person is some kinda whiney mall ninja.