Weird. 12 ga Barrel in a 20 gauge receiver? UPDATE

General discussion about Remington 870 shotgun.
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enbloc
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Weird. 12 ga Barrel in a 20 gauge receiver? UPDATE

Post by enbloc » Sat Aug 22, 2020 6:09 am

UPDATE:
This 2014 Remington Express 12 gauge shotgun has been confirmed by Remington Customer Service as being built as a 12 gauge shotgun.
CS also confirmed that the PREFIX "RS" and the SUFFIX "U" NO LONGER EXCLUSIVELY DENOTE a 20 gauge 870 shotgun.



Hi All,

I just bought a very clean, but used 870 12 gauge shotgun and have not fired it yet. It has a 28" vent-rib barrel with a Rem-Choke.
Bought from a private sale, no documents/manual/cardboard box.


Here's my issue:
After doing a serial number lookup I found that serial numbers on my 870 (RS prefix, U suffix) is a small frame 20ga frame.
It feeds, cycles, chambers and extracts 12ga A-Zoom practice rounds well. Frame is 1.33 inches wide.
I have a spare 18.5 inch 12 ga barrel that fits right in, so I know that the original barrel wasn't modified (If that is even possible?)

It looks just like this receiver. (except for the digits between the 'RS' and the 'U')
20190525143026-9111.jpg
20190525143026-9111.jpg (797.07 KiB) Viewed 3385 times
My questions are:
How does this 20 gauge receiver allow a 12 gauge barrel and mag tube fitment?
Is it safe to fire 12ga through it?
Is this actually a 12ga or a mismatched 12/20ga 870?
What the hell did I buy?

Thanks for any help...

~Enbloc
Last edited by enbloc on Mon Aug 24, 2020 4:21 pm, edited 5 times in total.

BKinzey
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Posts: 213
Joined: Fri Mar 27, 2020 6:57 pm

Re: Weird. 12 ga Barrel in a 20 gauge receiver?

Post by BKinzey » Sat Aug 22, 2020 9:24 pm

Somewhere around 1977 Remington changed the receivers on the 20ga to small frame. Previous to that the 12ga and 20ga were the same receivers.

When they made the change they also changed the size of the barrel ring and magazine so a "modern" 20ga barrel won't fit on a 12ga as the ring is too small. I haven't tried putting a modern 12ga barrel on a modern 20ga receiver but if it fit there would be an obvious gap between the ring and magazine.

I'd guess you have a 12ga but a call to Remington and checking your serial number would confirm it.

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enbloc
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Re: Weird. 12 ga Barrel in a 20 gauge receiver?

Post by enbloc » Sat Aug 22, 2020 9:36 pm

Thanks BKinzey,

This shotgun is only 5 years old. I think the 'New' serial number configuration is no longer accurate as to 'RS' prefix and 'U' Suffix being exclusive to the 20ga frame. My frame is 1.330" wide and that appears to be the 'large frame' chassis for a 12ga shottie.

I will call Remington on Monday and try and resolve what this 870 was when it left the factory, and post back what I find.

Thanks again,
~Matt

BKinzey
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Posts: 213
Joined: Fri Mar 27, 2020 6:57 pm

Re: Weird. 12 ga Barrel in a 20 gauge receiver?

Post by BKinzey » Sat Aug 22, 2020 9:47 pm

I'd measure my 20ga but it's like a 1968 year.

I have put a 12ga barrel on mine and 12ga shells will fit in the tube. Chamber too but I am a little too cautious to try firing. Will wait until a couple of reliable sources says it's ok.

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enbloc
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Re: Weird. 12 ga Barrel in a 20 gauge receiver?

Post by enbloc » Sat Aug 22, 2020 9:56 pm

1968 20ga 870 would be in the right age-range for the full-size receiver. Pre-1977 appears to be the cutoff.

887700
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Joined: Wed Oct 13, 2021 10:23 am

Re: Weird. 12 ga Barrel in a 20 gauge receiver? UPDATE

Post by 887700 » Wed Oct 13, 2021 10:49 am

Thanks very much for this info. It was driving me crazy because my 870 (like yours) has a RS/U serial but is def a 12 gauge. I purchased it black friday at Cabela's: 2014 sounds about right.

It's an express but doesn't say so on the gun. Came with a 28" barrel and a modified choke. COVERED in grease. Anyhow, glad I found this post because neither the date prefix of gauge suffix made sense and I couldn't find a phone number for Remington. My paperwork all checked out.

It'll be my slug gun this season using a Mossberg 24" smooth barrel with rifle sights.
enbloc wrote:
Sat Aug 22, 2020 6:09 am
UPDATE:
This 2014 Remington Express 12 gauge shotgun has been confirmed by Remington Customer Service as being built as a 12 gauge shotgun.
CS also confirmed that the PREFIX "RS" and the SUFFIX "U" NO LONGER EXCLUSIVELY DENOTE a 20 gauge 870 shotgun.



Hi All,

I just bought a very clean, but used 870 12 gauge shotgun and have not fired it yet. It has a 28" vent-rib barrel with a Rem-Choke.
Bought from a private sale, no documents/manual/cardboard box.


Here's my issue:
After doing a serial number lookup I found that serial numbers on my 870 (RS prefix, U suffix) is a small frame 20ga frame.
It feeds, cycles, chambers and extracts 12ga A-Zoom practice rounds well. Frame is 1.33 inches wide.
I have a spare 18.5 inch 12 ga barrel that fits right in, so I know that the original barrel wasn't modified (If that is even possible?)

It looks just like this receiver. (except for the digits between the 'RS' and the 'U')

20190525143026-9111.jpg

My questions are:
How does this 20 gauge receiver allow a 12 gauge barrel and mag tube fitment?
Is it safe to fire 12ga through it?
Is this actually a 12ga or a mismatched 12/20ga 870?
What the hell did I buy?

Thanks for any help...

~Enbloc

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