Evolution of the Remington 870 breech bolt and slide assembly

Very interesting post by redgoat on Remington 870 Forum:

This is more of a “here’s what I’ve observed” post than a how-to or an open ended question.

While researching all of the parts involved in the “flexi-tab conversion” for an older Wingmaster I learned that there is more involved than just switching the shell carrier to the new flexi-tab one. As I understand now, there can be up to four parts involved. I’ve listed them below along with their corresponding parts diagram number

1. The flex-tab shell carrier (part # 7)
2. The newer breech bolt with relief cut (part #4)
3. The newer slide assembly (part number 57)
4. The forend tube assembly (part # 28) (I believe that this is optional, but probably a good thing to include if making the conversion. However, note that a flexi-tab forend tube assembly will not work with the pre- flexi-tab breech bolt and slide assembly without modifying one of the slide rails on the tube assembly. I will post some pics which show why this is so).

I found that the various 870s that I have access to cover a surprising number of variations in these parts and so I have prepared a series of photos to document what I observed.

To get things started, here are some side-by-side photos of the variations I have noted.

Bolt / carrier #1 is from an old well preserved Wingmaster that had a 28″ fixed choke (modified) ribbed barrel.
Bolt / carrier #2 is from an _old_ 870 that appears to have been used by an LE organization. It is a Wingmaster, not a Police model, however.
Bolt / carrier #3 is from a recent Police Magnum model which apparently came with the flex-tab conversion.
Bolt / carrier #4 is from a new (2015) 870 Express, added for comparison, a “flex-tab conversion baseline”.

Evolution of the Remington 870 breech bolt and slide assembly
Evolution of the Remington 870 breech bolt and slide assembly

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Vitaly Pedchenko

My name is Vitaly Pedchenko, I started this blog and forum to share information, tips, photos, and advice about the Remington 870 shotgun, accessories, and upgrades. Now I also own AR-15 rifle and MP5 pistol caliber carbine. I am firearms instructor, competitive shooter and IPSC Range Officer. I participate in practical shooting and 3-Gun competitions because they are the best way for me to test equipment and upgrades under stress. I am member of the PRACTICA shooting club. I also participate in REAGO, which provides Tactical Combat Casualty Care training. The main purpose of the Rem870.com blog and forum is to have a compilation of information about the Remington 870 shotgun in one organized, accessible place.

One thought on “Evolution of the Remington 870 breech bolt and slide assembly

  • 13.03.2021 at 12:51

    What upgrade breech bolt should I buy for my 870


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