Can i ask why you make the prediction that the BPS would break down before the Wingmaster?
I believe the feed ramp is stronger on the 870 as it is a single stamped piece of metal.
The feed ramp as I call them is the piece that takes ammo from the magazine and creates a ramp so shells can be pushed up into the chamber
The browning has 2 arms that run parallel to the receiver. 1 on both side of the chamber that cradle the ammo lengthwise. When the gun is empty, cycle the action slowly while its upside down so you can see in. During the forward stroke you will see the 2 arms *raise up* or in our case *lower down* because the gun is upside down. You will see that they get spread apart as the bolt travels through them and then when reaching a full stroke they sort of snap back into place. Then try it again with a shell, the effect is more noticeable. I'm sure a piece of high tensile strength?? metal was used for the feedramps to endure this type of spreading and release. I feel it is a weak point. I just don't like that it does that but mine hasn't worn out nor have I heard other complaints about it being a problem.
Keep in mind it is just a prediction and I have no evidence to back it up. As I said though, I doubt very few of either will see enough shells to wear them out.