The Firing Line Forums

Go Back   The Firing Line Forums > The Hide > The Dave McCracken Memorial Shotgun Forum

Thread Tools Search this Thread
Old February 7, 2018, 09:37 AM   #1
Senior Member
Join Date: October 28, 2011
Posts: 535
Remington 870 question

Hello all. I recently picked up an very nice 870 12 gauge used. On the barrel it says 3 1/2 cinch shells with magnum receiver only. How do I know if I have a magnum receiver? The receiver only reads “Remington 870” then has the serial number on it. Thanks in advance.
bspillman is offline  
Old February 7, 2018, 09:44 AM   #2
Senior Member
Join Date: May 16, 2012
Location: New Jersey
Posts: 611
If the serial number ends in M, it is a 3” receiver. If it ends in A, it is a 3.5” receiver.

You can put a 3.5” barrel on a 3” receiver... but will only be able to function with 3” shells.
Screwball is offline  
Old February 7, 2018, 09:49 AM   #3
Senior Member
Join Date: November 4, 2013
Location: Western slope of Colorado
Posts: 3,181
And remember the 3” (or 3.5”) length is based on the FIRED (unfolded crimp) length. So, you can fit a 3”shell in a 2.75” chamber and it will fire. But there is no space for the crimp to unfold into. The result is increased and unsafe chamber pressure

Im not sure about the interaction with a 3.5” shell in a 3” chamber. It might not chamber at all. Even if it does, it is not safe to fire.
Sharkbite is offline  
Old February 8, 2018, 02:09 PM   #4
Senior Member
Join Date: October 28, 2011
Posts: 535
My serial number is RS17940Z
bspillman is offline  
Old February 8, 2018, 06:05 PM   #5
Senior Member
Join Date: February 11, 2012
Location: Williamsburg, Va.
Posts: 1,390
Ah, the new numbering system tells you NOTHING other than it is a Remington Shotgun - RS. All Supermagnum 3-1/2" receivers are supposed to say that on the receiver, but I wouldn't trust that. Get a FIRED 3-1/2" hull with an unfolded crimp, and put it in the chamber and see if it will eject. If it will you have a Supermagnum receiver. The Supermagnum receiver is different than the 2-3/4" and 3" receivers, but the barrels will interchange.
My bet is you have a regular 3" Magnum receiver, but NOT a 3-1/2" Supermagnum receiver.
What could have happened... did.

I do not trust Remington's dating service accuracy. If they were, you could end up with Nancy Pelosi.
Virginian is offline  
Old February 8, 2018, 09:15 PM   #6
Senior Member
Join Date: May 4, 2001
Posts: 7,190
The Super Magnum 870 has a longer ejection port.

At least the older models had a piece of black plastic at the rear of the bolt to cover the open space at the rear of the longer ejection port.

If you email Remington and give them the serial number they'll tell you what it is:
Dfariswheel is offline  

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 02:37 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2018 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent:
Contact Us
Page generated in 0.05376 seconds with 10 queries