What is this part?

[rdsmith3]

I was disassembling my shotgun to clean it, and I noticed this small part on the table (the little thing next to the orange follower). What is it? Where does it go?

[vmax]

Looks like a magazine cap detent. it goes into a small hole on your barrel ring. Located on the bottom of your barrel there is a ring that slides over the tube magazine when you remove or install it. the detent keeps the mag cap tight

[Vitaly]

rdsmith3, vmax,

What Remington 870 variant has that part? Police?

[rdsmith3]

I e-mailed Remington to ask them what it is.

[badboybeeson]

I e-mailed Remington to ask them what it is.

it is the barrle dedent, you should be looking for a small spring as well.
bbb

[vmax]

As stated before it is a magazine cap detent PN #F17451. It fits over a small spring in a hole in your barrel ring. I have a pic for you. One has detent the other has only a small hole for a detent. Don't worry it is not completly nessesary. There are other ways to keep your mag nut tight. Use a rubber o ring that fits over the treads of your magazine or a wave washer from a remigton 1100 forend. When installed before you screw on your mag nut they will keep the nut tight. Also replacing the detent and spring is a quick job for your gunsmith. To hold the spring and detent in the barrel ring will have to be staked.

[rdsmith3]

Thanks. I am not happy that this thing popped out. I just bought it in December.

[RichNZ]

Nice spotting Vmax.

It was on the tip of my brain, just couldn't connect the two.