Ok. So I got them all stripped again, and I believe I Now have the pics needed to properly show some of you the differences between these two war horses. This may be more than one post depending on how many images, I can upload at once.
I’ll start at the barrel, and work back from there.
By now, we’ve established the 590 barrel is heavier, but what about the means to secure it?
On both the 870 and 590, they are secured in place by the same manner. A cap that threads onto the mag tube over a sleeve that is attached to the barrel. The caps are both steel, but they have a different approach as to how they obtain the same result.
The Mossberg is on the left, and the Remington is right. Those little spikes are for a ball detent to engage and keep them from rotating under use. As you can see, the mossberg has it on the outside, and the Remington has them recessed into the cap.
The reason the Mossberg has it on the outside, is to engage the ball detent that is located on the barrel sleeve shown here.
The Remington barrel does not have this detent. Instead it relies on the magazine spring retainer to provide tension to keep the cap from working loose.
Whether or not one is more effective than the other is debatable. Also, this style of cap is called an internal ratchet design, and not the external. The external is found on models other than the express, and are much closer to the 590 system.
Barrels?
The Remington barrel differs from the Mossberg in a few ways. Not only are the cutouts for the extractors different, but the bolt lugs are as well.
The Mossberg barrel has a hole for the lug to engage. The Remington has a machined area for their lug. I prefer the Mossberg style over the Remington in this area.
The mag tubes themselves are very similar, but they still differ in a few small ways. On the Mossberg, it is serviceable, and user replaceable, but not exactly easy. But it threads into the receiver. The Remington however, is not user serviceable, and should not be removed or modified. It has a block on top of it to guide the action arms.
The 590, has a similar design for the arms to ride in, but just a different approach.
Now for the forends. This is one of two things that most people notice immediately when picking up either of these guns.
On the Mossberg, the forend your typical tube, but its action arms are able to move. Theres a reason why they have this movement. It is because they are replaceable. They are pinned in place and have tension on them.
Here you can see Im pushing up on the left one and there is a bit of positive resistance.
When a forend is installed, you cant see the pins.
Now on the 870, the arms are stationary. The tube and arms are sold as one unit. You can see how they are machined to the tube.
The reason I feel this is important, is Ive seen countless people try to tell me that when they pick up the Mossberg, it feels cheap, and has movement. This is the movement they’re talking about. The arms are allowed to move to reduce the possibility of damage if you’re not pulling strait back. It does allow the forend to flex a little bit. But most people dont know this is part of the design. The Remington is much more robust feeling, with less movement, but it doesn’t necessarily equate to a stronger product. I like both designs honestly.
Now the receiver internals.
This is where things can get some people confused. They both have the same parts, just different ways to execute the same process.
On the 870, the ejector is riveted into place. It can be user replaced but not easily if you dont have access to the tools to do it properly.
On the 590, it is screwed into place snd easily swapped out if need be.