This topic comes up from time to time and I had to convert a few earlier guns to Flexi-tab today, so I took photos of the parts so you guys could quickly see the differences and be able to ID them more readily.
First of all, some people are going to click on this thread and not have heard of a "flexi tab". Basically, on earlier 870's, if you were loading a cartridge into the magazine and cleared the elevator tab, but didn't push the shell hard enough to have it travel past the shell latches, it could pop past the latches and up above the cartridge elevator. Prior to Remington re-designing the 870, this resulted in a serious jam that sometimes necessitated pulling the trigger plate off the gun to clear it.
The Flexi-Tab conversion re-designed the bolt slide, the bolt, and the cartridge elevator such that a round that misfeeds as described above can be easily cleared by cycling the action with a marginal amount of extra force. Why is this important? Well, it was first thought up for duty shotguns where people operated them (potentially) ham-fistedly in high-stress situations. It proved so successful, that other users (such as bear defence customers) wanted the same functionality. Today, virtually all new 870's leave the factory with Flexi-Tabs.
So let's discuss the differences in the parts themselves. Here we have a pair of Wingmaster bolts. The one on the left is from a 1990's Wingmaster, the one on the right is out of a 1970's Wingmaster.
Look at the area on the bottom of the bolt just below the bolt face. On the newer bolt, you will notice there is a machined-away area that creates a recessed flat. This clearance cut forms part of the Flexi-tab re-disign and if your bolt does not have this feature, it would need to be replaced if you want flex-tab functionality in your shotgun. The bolts are otherwise identical.
Now we look at the bolt slides. the slide on the left is an early one and is not flex-tab compatible. the one on the right is an early flex-tab carrier from the early 1990's. The only difference of consequence, and the only one that has anything to do with flexi-tab functionality are the two little "ramp" cuts on either side of the slide, at the very back, where the slide starts to be rounded. The other differences are just normal manufacturing differences, as Remington changed the design in other way over time - ways that have nothing to do with Flexi-tab function.
Here's a close-up picture of the flexi-tab compatible slide sitting in the carrier's action bars.
the next couple pictures show a 2015 made slide next to an early 1990's slide. Both of these slides are flexi-tab compatible, but the 2015 part has an extra action bar notch cut into it to increase the surface area for a new-style carrier (action bars). All slides are backwards compatible, but you need one with the noted "ramp" cuts at the back end to ensure flexi-tab functionality.
Here are the bottoms of the same parts that show the extra notch for the new-type carrier (action bar) assembly. If you have a new style carrier, you also need a recent manufacture bolt slide (like the one pictured here on the right) as the older ones will not fit without some modification (i.e. cutting this notch into your older slide). The extra notch for the newer carriers has nothing to do with Flexi-tab functionality though!
Now we look at the cartridge elevators.
On the left is an early elevator, it is NOT Flexi-tab compatible. On the right is a flex-tab elevator. The "U-shaped" cut in the elevator is what makes it Flexi-tab compatible. This tab flexes outward when the rim of a jammed shell rides over it as a user cycles the action on a jammed round. This flexing tab, coupled with the extra clearance below the bolt face, and the ramps at the back of the slide that allow the bolt to slightly tilt just as it leaves battery, have the combined effect of letting you cycle the action open over a jammed shell. This lets the round feed and then eject normally.
So, in summary, these are the three parts you need to convert an earlier 870 to be Flexi-tab compatible.
As a closing note, if you don't have a flexi-tab gun and you get a feed jam in a high-stress situation, the proper drill is to point the muzzle up and away from you, grip the gun around the action with a finger depressing the slide release, and your other hand on the slide. Now slam the butt down on a firm surface HARD as you try to cycle the slide. This will usually eject the jam, but there is also a good chance you will crack the buttstock. Don't do it this way unless it's a real emergency. It's also pretty hard on your gun.
First of all, some people are going to click on this thread and not have heard of a "flexi tab". Basically, on earlier 870's, if you were loading a cartridge into the magazine and cleared the elevator tab, but didn't push the shell hard enough to have it travel past the shell latches, it could pop past the latches and up above the cartridge elevator. Prior to Remington re-designing the 870, this resulted in a serious jam that sometimes necessitated pulling the trigger plate off the gun to clear it.
The Flexi-Tab conversion re-designed the bolt slide, the bolt, and the cartridge elevator such that a round that misfeeds as described above can be easily cleared by cycling the action with a marginal amount of extra force. Why is this important? Well, it was first thought up for duty shotguns where people operated them (potentially) ham-fistedly in high-stress situations. It proved so successful, that other users (such as bear defence customers) wanted the same functionality. Today, virtually all new 870's leave the factory with Flexi-Tabs.
So let's discuss the differences in the parts themselves. Here we have a pair of Wingmaster bolts. The one on the left is from a 1990's Wingmaster, the one on the right is out of a 1970's Wingmaster.
Look at the area on the bottom of the bolt just below the bolt face. On the newer bolt, you will notice there is a machined-away area that creates a recessed flat. This clearance cut forms part of the Flexi-tab re-disign and if your bolt does not have this feature, it would need to be replaced if you want flex-tab functionality in your shotgun. The bolts are otherwise identical.
Now we look at the bolt slides. the slide on the left is an early one and is not flex-tab compatible. the one on the right is an early flex-tab carrier from the early 1990's. The only difference of consequence, and the only one that has anything to do with flexi-tab functionality are the two little "ramp" cuts on either side of the slide, at the very back, where the slide starts to be rounded. The other differences are just normal manufacturing differences, as Remington changed the design in other way over time - ways that have nothing to do with Flexi-tab function.
Here's a close-up picture of the flexi-tab compatible slide sitting in the carrier's action bars.
the next couple pictures show a 2015 made slide next to an early 1990's slide. Both of these slides are flexi-tab compatible, but the 2015 part has an extra action bar notch cut into it to increase the surface area for a new-style carrier (action bars). All slides are backwards compatible, but you need one with the noted "ramp" cuts at the back end to ensure flexi-tab functionality.
Here are the bottoms of the same parts that show the extra notch for the new-type carrier (action bar) assembly. If you have a new style carrier, you also need a recent manufacture bolt slide (like the one pictured here on the right) as the older ones will not fit without some modification (i.e. cutting this notch into your older slide). The extra notch for the newer carriers has nothing to do with Flexi-tab functionality though!
Now we look at the cartridge elevators.
On the left is an early elevator, it is NOT Flexi-tab compatible. On the right is a flex-tab elevator. The "U-shaped" cut in the elevator is what makes it Flexi-tab compatible. This tab flexes outward when the rim of a jammed shell rides over it as a user cycles the action on a jammed round. This flexing tab, coupled with the extra clearance below the bolt face, and the ramps at the back of the slide that allow the bolt to slightly tilt just as it leaves battery, have the combined effect of letting you cycle the action open over a jammed shell. This lets the round feed and then eject normally.
So, in summary, these are the three parts you need to convert an earlier 870 to be Flexi-tab compatible.
As a closing note, if you don't have a flexi-tab gun and you get a feed jam in a high-stress situation, the proper drill is to point the muzzle up and away from you, grip the gun around the action with a finger depressing the slide release, and your other hand on the slide. Now slam the butt down on a firm surface HARD as you try to cycle the slide. This will usually eject the jam, but there is also a good chance you will crack the buttstock. Don't do it this way unless it's a real emergency. It's also pretty hard on your gun.
On my DA, I only replaced the elevator. I still have to figure out what to do with the other parts - I have not even checked if Remington pars interchange yet - been too busy.
