I have a 12 gauge 1953 Remington 870 Wingmaster Magnum shotgun. There is about a 4-5 inch heavy, solid metal bar that is the magazine plug. It is held in place with a single screw through the magazine tube. It is very well made and nicely blued, matching the guns original finish perfectly. The standard 870 barrel retaining cap covers and hides the screw.

A gunsmith recently told me that he thinks that is an aftermarket modification and not factory; he says they did it for balance.

Does anyone know if this is factory or a modification?

If a modification which spring steel/friction cap should I look for to bring the gun back to original?

This is a very nice 870 wingmaster with tootsie roll pump and highly figured oil finished stock (factory finish). It has a 30 inch Full choke plain barrel on it. I also have a much later 28 inch lightweight 12 gauge VR/RC barrel for upland bird hunting.

The ejection port is 2.950" and I believe it to be factory original.

The magazine plug is 4.50" x .910"

I do have the original barrel and here are some pics.

Further research indicates this is a factory item, the Vari-weight Plug, 12 oz. blued steel. Offered from 1950 until at least 1972, which is the latest Gun Digest I have with it listed. Perhaps Gun Digest never updated and deleted the Vari-weight plug.

Maybe to tone down recoil and muzzle jump with Magnum loads?