I want a shorter barrel for one of my 870 Wingmasters. I dont want to cut off one of my barrels, and I see aftermarket 18.5" barrels for sale, but they don't specify Wingmaster, so I'm guessing they are for 870 Expresses.

Will they interchange?

Yes.

Thanks.

As long as yours isn't a Special Field or a model with a Light Contour barrel.

Both of mine say Remington Magnum Wingmaster 870 on the receiver. 12 ga. Magnum for 3" shells on the barrel.

Nothing about Special Field or Light Contour barrel.

Then you are good to go.

Even a barrel with a 2 3/4"chamber will work fine, just can't use a 3" shell in said barrel.

The only issue with putting a standard contour barrel on an 870 that came with a light contour is the forearm channel may be a little tight.

They'll interchange, but will shoot loose because the magazine caps lock differently.

The Wingmaster barrels have a ball detent that locks the Wingmaster magazine cap. The Express uses a toothed-plastic magazine spring retainer that engages internal teeth on the Express magazine cap.

Early Expresses had the same ball detent arrangement {and aluminum trigger guard} as Wingmasters. I would think any new 18.5" 870 security barrel would need to have it too so they'd work on any 870 with either retaining system.

Unless "Express" is specified the barrels should have detents. Just browsing a bit, the only "870 Express" barrels that I saw were Carlson's at Midway. They're probably mislabeled though as there are detents on the pictured barrels, and they aren't listed as "870 Express" on Carlson's site.

The aluminum Express trigger guard to which you're referring is the one prior to the polymer guards?

Yes.

The early Express that I have (with an aluminum trigger guard) has a detent sans ball and spring.

Mine has the ball and spring.