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Mossberg 500 Pump Action Troubleshooting

6 3/4" forend interchangable with the 7 5/8"?

Hello, new guy here coming from shotgunworld.com. Thought I'd ask this here since it's specific to Mossbergs.

The 500 in question is a JIC Mossberg Mariner.

I purchased an ergo 3 rail forend from midway. Unfortunately I have the 7 5/8" action assembly tube that this will not fit on or in. Didn't see any details on midways site and didn't realize it until I saw the packaging once it arrived.

My easy solution is to find the ergo 3 rail long version that fits my tube but midway does not stock them and they seem to be discontinued as ergo grip does not even sell them directly.

So my question is will the 6 3/4" assembly tube fit and function on my 500? I have scoured google and this site for the answer but all I kept seeing was that the pinned forends will interchange. Mine is not the pinned but simply the longer version. I would like to know if the shorter tube assembly will swap out without issue.

Otherwise I'll just have to return the ergo and try out the laserlyte trirail. Other thing is that I bought some larue tactical handstops and rail covers to use and I can't exactly return those.

Any help is appreciated.
 
Re: 6 3/4" forend interchangable with the 7 5/8"?

Honestly, I thought the shorter action slides were just on the 3-1/2 chambered pumps. I thought that most aftermarket fore-ends catered to the longer action tube. I have an 835 and it has the shorter tube and I had to modify my fore=end and use a Hogue 1 inch action tube nut to make it work.

Looks to me that the JIC series should be just like the 500's with the longer action tube.If you have a fore-end for the short action tube, it should be for an 835 of 535 with the 3-1/2 chamber.

Guys, feel free to correct me. I had a couple of early glasses of Christmas cheer. :D
 
Re: last round falling out

Did you ever get it fixed?

My suggestion would be field strip it, clean and lube and put it back together and try again,

While you have it stripped down inspect everything but mostly the cartridge stop and cartridge interrupter.

When the bolt pulls back first the cartridge interrupter is pushed out to catch the following shell then the cartridge stop is pulled back allowing the spring in the magazine to dispense one shell. When the bolt closes, the reverse is done allowing the next shell to end on the cartridge stop, readying it for the next cycle.

I hope I made this a little bit clearer that the last cup of coffee after the pot has set on the hotplate all day.
 
Re: 6 3/4" forend interchangable with the 7 5/8"?

I would have thought that since most of the newer synthetic forends on 500's and 590's are the longer 7 5/8" version that they would cater to that version as well. For whatever reason I can't find one for sale but the 6 3/4" one is available at a lot of different places. :?

I'm certain mine is 7 5/8" as it currently has the hogue forend with the stock castle nut and I measured it to make sure.
 
Re: 6 3/4" forend interchangable with the 7 5/8"?

I would talk to Victor or Cheryl of Havlin Sales! They'll know for sure if you would have any problems going from one to the other and they may have the shorter tubes as well!

www.havlinsales.com

You can call or email, just say Hi! for us!!! ;)
 
Re: last round falling out

No I have not had a chance to look at it.
I am hoping to have some time this week to do a compete tear down of the gun and clean it up.
I will let you know if I find/solve the problem.

Nasa, thanks for the explaning the process.
 
Re: 6 3/4" forend interchangable with the 7 5/8"?

It should inter change and then take the short forend.

Sent from Droid Incredible on Verizon Wireless
 
Re: 6 3/4" forend interchangable with the 7 5/8"?

Yep, should interchange .I havent done it but read of others that did.
 
Re: 6 3/4" forend interchangable with the 7 5/8"?

I didn't know anything about the 500 having different length forends either, until I got my ergo rail.

That is another big quirk I have against mossbergs. They seem to have a difficult time settling on one particular setup. Even in the same models.

I ended up with the long forend (needed the short) and what I did was use a hacksaw and cut off the extra length as necessary.

I don't remember how much specifically that I cut off, but I could count the rail slots if that would help.
 
Re: 6 3/4" forend interchangable with the 7 5/8"?

Thanks for the confirmation guys. I also found some threads that confirmed it will swap out over at SGW.

Weird thing is that my 7 5/8" forend tube is a lot thicker than the ergo forend slot. I thought it was for a 20 ga at first or an 870. Tried it on my 870 12ga and it was way to long but fit.

I'll be ordering the shorter forend and keeping the hogue on the longer one so I can swap them out when I go trap shooting or want a light attachment.
 
Re: 6 3/4" forend interchangable with the 7 5/8"?

John A. said:
I didn't know anything about the 500 having different length forends either, until I got my ergo rail.

That is another big quirk I have against mossbergs. They seem to have a difficult time settling on one particular setup. Even in the same models.

I ended up with the long forend (needed the short) and what I did was use a hacksaw and cut off the extra length as necessary.

I don't remember how much specifically that I cut off, but I could count the rail slots if that would help.
Click to expand...

That's weird. My forend tube does not fit in the ergo rail. It's labeled model 4586 for mossbergs and is shorter but the other thing is the diameter of the action tube is larger than the ergo rail. Is it supposed to fit but just be too long?

If so I may have gotten a completely wrong model. There is only the packaging to refer to as there are no markings on the ergo rail that say the model number.

This is another reason I asked if the action tube was interchangeable since i figured it may be a different size when I got it and would not work.
 
Re: 6 3/4" forend interchangable with the 7 5/8"?

Mine fit, other than being an inch or so too long for the nut to go on.
 
Re: 6 3/4" forend interchangable with the 7 5/8"?

So my question is will the 6 3/4" assembly tube fit and function on my 500? I have scoured google and this site for the answer but all I kept seeing was that the pinned forends will interchange. Mine is not the pinned but simply the longer version. I would like to know if the shorter tube assembly will swap out without issue.

Ghost,

The short answer is yes, they will interchange.

I'm rather curious about the forend not fitting. I recently installed a speed forend on a mossberg and the instructions that came with it refered to a spacer that was to be used on the 6 3/4" tubes to make up difference in length.
 
Re: 6 3/4" forend interchangable with the 7 5/8"?

Gunner said:
So my question is will the 6 3/4" assembly tube fit and function on my 500? I have scoured google and this site for the answer but all I kept seeing was that the pinned forends will interchange. Mine is not the pinned but simply the longer version. I would like to know if the shorter tube assembly will swap out without issue.

Ghost,

The short answer is yes, they will interchange.

I'm rather curious about the forend not fitting. I recently installed a speed forend on a mossberg and the instructions that came with it refered to a spacer that was to be used on the 6 3/4" tubes to make up difference in length.
Click to expand...

So the forend I got was actually the right size. The labeling was wrong on the forend. It said it was for a 6 3/4" and my forend was the 7 5/8" one. Too bad I ordered a 6 3/4" forend from midwayusa and installed it just to figure it out. The model I received is a 4865L and it clearly states 4865 on the label (and 'fits 6 3/4" forends only.') I emailed ergogrips.net with some questions but never got a response.

After seeing Rossignol's thread on his review of the rail and how the installation was tight, I went ahead and used a rubber mallet to fit it on. It's a super tight fit but it's on there now. The diameter was correct but it doesn't appear so at first glance. I had to really squeeze it in. I was scared I was gonna ruin the fine threads but they held.

I wasted $40 on an extra tube though and bulged the threads trying to drive the short tube out with a socket. Had the label been correct or the forend actually labeled, and had I found Rossignols thread sooner I could have saved some time and money. :x

Lesson learned.
 
Re: 6 3/4" forend interchangable with the 7 5/8"?

Sorry to hear you went through all that.

I can get you a contact name for ERGO, but have emailed them myself in the recent past without response also.

You may be able to call and get through.
 
Re: 6 3/4" forend interchangable with the 7 5/8"?

Check your PM box for Ergo contact info
 
Re: 6 3/4" forend interchangable with the 7 5/8"?

ghost,
Good to hear you have it well in hand and are making progress. I agree it can be an expensive pita when dealing with mislabeled parts.
 
Not exactly a troubleshooting question, but this forum seemed to be the best match. When did Mossberg make the following changes to their product?

1) Double action bars
2) Plastic safety
3) Plastic trigger guard

I bought my Mossberg 500 in 1964, and it had none of those items.

Thanks.

- massmanute -
 
Breacher Barrel Specs?

Hey guys I have the 500 Breacher Barrel on my Persuader Cruiser and I was wondering if anyone knows if these are the same profile (thickness) as the 590A1 barrels. It seems really think....a lot thicker than they standard 500 barrel.

Thanks guys

Jason
 
Re: Breacher Barrel Specs?

I do not have the exact dimensions but it is certainly a heavy walled barrel.
 
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