Rem 870 - What am I Doing Wrong

jackstrawIII · August 15, 2020, 09:59 PM

Hey guys. Tried to install a new Magpul forend onto my 12 gauge 870. Everything went together fine, but the forend won't slide over the receiver when you pull the pump/slide back.

It's like it was made for a narrower receiver... which doesn't make sense.

What am I doing wrong?

zoomie · August 15, 2020, 10:20 PM

What does your serial number end in?

jackstrawIII · August 17, 2020, 08:56 AM

Serial ends in 7699M

zoomie · August 17, 2020, 10:32 AM

Well there goes that theory. If you'd said "A" that's a Super Mag and it's not compatible.

Can you post a picture of what's binding? The forend won't cover the receiver much at all even when it's full aft.

Sharkbite · August 17, 2020, 11:09 AM

Installed backwards??? Just guessing

tango1niner · August 18, 2020, 06:26 PM

Can you eject a fired shell?

Pahoo · August 18, 2020, 07:42 PM

I don't see how you can put it on backwards as you would not be able to install/fit, the magazine tube castle nut. ....

Be Safe !!!

jackstrawIII · August 19, 2020, 09:03 AM

Quote:

I don't see how you can put it on backwards as you would not be able to install/fit, the magazine tube castle nut. ....

Yeah, I'm pretty sure it's not backwards.

As far as ejecting, the forend assembly it won't even go on far enough to "lock" back in place. The slide rails will go in a few inches until the magpul part hits against the receiver, but then the whole forend assembly will pull right back out again and separate from the receiver entirely.

jackstrawIII · August 20, 2020, 07:47 PM

This is how far back it goes. See how the bolt isn't fully retracted? For some reason, the slide just won't fit over the receiver. I don't know what's wrong here. The forend just looks too small.

Are there multiple sizes?
https://www.dropbox.com/s/h8ovqnf4bj...34.41.jpg?dl=0

CowTowner · August 21, 2020, 03:52 PM

After looking at the picture zoomie posted and the linked picture from the OP, I'd say it looks to be mounted backwards. But, I've never installed one of these myself.

burrhead · August 22, 2020, 09:54 AM

What did Magpul say when you called them?

zoomie · August 22, 2020, 09:56 AM

Looks backwards. The M-LOKs go on the front and the more aggressive slope should be aft.

skywag · August 22, 2020, 10:31 AM

You have to stick your left hand mid finger in there and hold the rail to the inside receiver wall. Then it will slide back into place.

See 8:10 in this video
https://youtu.be/ZgmxcN6_78Y

jmr40 · August 22, 2020, 03:10 PM

The photo the OP posted is backwards compared to the original photo. One of them is backwards. I didn't think it was possible to get a forend on backwards.

jackstrawIII · August 22, 2020, 03:37 PM

Well, there you go. Looks like I put it on backwards. Haha I knew I was doing something wrong.

Thanks all. I’ll go hide in shame now haha.

big al hunter · August 22, 2020, 05:42 PM

Quote:

Thanks all. I’ll go hide in shame now haha

No need to hide. A wise person asks when they don't know. A fool would have grabbed a hammer and Dremel to "make it fit". Good on you for being willing to ask.

**Spats McGee** · August 23, 2020, 09:19 AM

Quote:

Originally Posted by big al hunter

No need to hide. A wise person asks when they don't know. A fool would have grabbed a hammer and Dremel to "make it fit". Good on you for being willing to ask.

^^^ Absolutely!

ms6852 · August 23, 2020, 09:32 AM

Quote:

Originally Posted by big al hunter

No need to hide. A wise person asks when they don't know. A fool would have grabbed a hammer and Dremel to "make it fit". Good on you for being willing to ask.

This always ^^^^^^^^

stagpanther · August 24, 2020, 02:55 PM

Quote:

A fool would have grabbed a hammer and Dremel to "make it fit".

What? That's how I get half my stuff together.

August 15, 2020, 09:59 PM	#1
jackstrawIII Senior Member Join Date: July 20, 2016 Location: Upstate NY. Posts: 912	Rem 870 - What am I Doing Wrong Hey guys. Tried to install a new Magpul forend onto my 12 gauge 870. Everything went together fine, but the forend won't slide over the receiver when you pull the pump/slide back. It's like it was made for a narrower receiver... which doesn't make sense. What am I doing wrong? __________________ In God we trust.

August 17, 2020, 08:56 AM	#3
jackstrawIII Senior Member Join Date: July 20, 2016 Location: Upstate NY. Posts: 912	Serial ends in 7699M __________________ In God we trust.

August 18, 2020, 07:42 PM	#7
Pahoo Senior Member Join Date: February 16, 2006 Location: IOWA Posts: 8,783	???? I don't see how you can put it on backwards as you would not be able to install/fit, the magazine tube castle nut. .... Be Safe !!! __________________ 'Fundamental truths' are easy to recognize because they are verified daily through simple observation and thus, require no testing.

August 20, 2020, 07:47 PM	#9
jackstrawIII Senior Member Join Date: July 20, 2016 Location: Upstate NY. Posts: 912	This is how far back it goes. See how the bolt isn't fully retracted? For some reason, the slide just won't fit over the receiver. I don't know what's wrong here. The forend just looks too small. Are there multiple sizes? https://www.dropbox.com/s/h8ovqnf4bj...34.41.jpg?dl=0 __________________ In God we trust.

August 21, 2020, 03:52 PM	#10
CowTowner Senior Member Join Date: October 17, 2007 Location: Cowtown of course! Posts: 1,747	After looking at the picture zoomie posted and the linked picture from the OP, I'd say it looks to be mounted backwards. But, I've never installed one of these myself. __________________ NRA Chief Range Safety Officer, Home Firearms Safety, Pistol and Rifle Instructor *“Today, we need a nation of Minutemen, citizens who are not only prepared to take arms, but citizens who regard the preservation of freedom as the basic purpose of their daily life......”* President John F. Kennedy

August 15, 2020, 10:20 PM	#2
zoomie Senior Member Join Date: January 23, 2006 Location: GA Posts: 1,870	What does your serial number end in?

August 17, 2020, 10:32 AM	#4
zoomie Senior Member Join Date: January 23, 2006 Location: GA Posts: 1,870	Well there goes that theory. If you'd said "A" that's a Super Mag and it's not compatible. Can you post a picture of what's binding? The forend won't cover the receiver much at all even when it's full aft.

August 17, 2020, 11:09 AM	#5
Sharkbite Senior Member Join Date: November 4, 2013 Location: Western slope of Colorado Posts: 3,822	Installed backwards??? Just guessing

August 18, 2020, 06:26 PM	#6
tango1niner Senior Member Join Date: March 6, 2009 Location: NY Posts: 324	Can you eject a fired shell?

August 22, 2020, 09:54 AM	#11
burrhead Senior Member Join Date: July 7, 1999 Location: Chihuahuan desert, Texas Posts: 1,149	What did Magpul say when you called them? __________________ Join the GOA, SAF and the TSRA I'm offended by people that are easily offended.

August 22, 2020, 09:56 AM	#12
zoomie Senior Member Join Date: January 23, 2006 Location: GA Posts: 1,870	Looks backwards. The M-LOKs go on the front and the more aggressive slope should be aft.

August 22, 2020, 10:31 AM	#13
skywag Senior Member Join Date: February 24, 2011 Posts: 256	You have to stick your left hand mid finger in there and hold the rail to the inside receiver wall. Then it will slide back into place. See 8:10 in this video https://youtu.be/ZgmxcN6_78Y

August 22, 2020, 03:10 PM	#14
jmr40 Senior Member Join Date: June 15, 2008 Location: Georgia Posts: 10,974	The photo the OP posted is backwards compared to the original photo. One of them is backwards. I didn't think it was possible to get a forend on backwards. __________________ "If you're still doing things the same way you were doing them 10 years ago, you're doing it wrong" Winston Churchill

August 22, 2020, 03:37 PM	#15
jackstrawIII Senior Member Join Date: July 20, 2016 Location: Upstate NY. Posts: 912	Well, there you go. Looks like I put it on backwards. Haha I knew I was doing something wrong. Thanks all. I’ll go hide in shame now haha. __________________ In God we trust.