870 12 GA Action Bar/Tube Assembly Compatibility

[DaveinBrig]

In the Remington 2014 Parts Price List, for the 870 12 gauge action bars, it lists part number F102324 and the part description reads, "FORE END TUBE ASSEM N/S 12 GA (FOR PRE-1984 GUNS INCLUDE SLIDE F401023)". Is there any difference in the pre-1984 action bars and the 1984 and newer action bars or are the action bar/tube assemblies completely interchangeable?

[Synchronizor]

The major difference between the new- and old-style fore-end tube assemblies relates to the parts of the action bars that the slide assembly sits in. There are a couple other minor differences, but this is the only one that should affect parts compatibility.

New-style slide assemblies have an extra cut-out on the left side that old-style slide assemblies don't have (click the picture below for a larger version).



New-style action bars have an extra tab that fits into this cut-out, while old-style action bars don't. This means that you can use both old- and new-style slide assemblies with an old-style fore-end tube assembly, but if you have a new-style fore-end tube assembly, you have to use a new-style slide assembly.

[DaveinBrig]

Thank you for that information. That answered my question as to difference between the pre and post '84 tube assemblies. I have seen tube assemblies advertised for sale online and they never stipulate whether they are the old or new style so I would have to determine that myself from the pictures. If I inadvertently ended up with a new style tube assembly could I grind the extra tab off of the action bar so that it would work with my old style slide or is this not advisable?

[Synchronizor]

You could probably get an old-style slide assembly to work with new-style action bars if you had to, I can't imagine any major functional problems with cutting off that tab if you do it carefully.

However, for the amount of time and effort you'll probably spend cutting, grinding, sanding, and so on, you might as well just order a new-style slide assembly from Remington. They're under $25 if I remember correctly (check your parts list for the different options & prices), and they'll drop right into older guns and function more reliably than the original part (though you also need to install new-style breech bolt and carrier assemblies to really get the benefit of the improved parts, see this video for details).

[DaveinBrig]

Thank you very much. Your information has been very helpful.