Need help picking up a Mossberg 500A foregrip.


May 21, 2009, 05:16 PM
Apparently mossberg changed their mag tube design and some after market foregrips will not fit models produced after 2006. I purchased my mossberg in 2006 so how can I tell if mine falls under the new design?

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May 21, 2009, 06:33 PM
Simply put, if your gun came with a wood forearm, yours is a Mossy 500 forearm/action tube. If it's plastic....

If the action bars, the two bars that attach to the forearm, are riveted directly to the plastic, it's a Mav 88 forearm and you can't be replaced with an aftermarket one as is. You'd need to replace yours with a Mossberg 500 action tube to be able to use aftermarket grips.

If the bars on yours attach to a steel tube that the wood or plastic forearm is slid down onto and there's a 2 notch nut at the front that can be unscrewed, yours is a Mossy 500 action slide tube and aftermarket grips will fit as long as they're the right length.

This is a 500 slide tube. ( The bars attach to the tube, not the wood or plastic forearm.

This is a Mav 88 forearm. ( The bars are riveted to the plastic and there's no steel tube.

Length....newer Mossy's have a 6 5/8" long action slide tube....again, the steel tube the wood forearm slides down onto. But, pretty much all, all I've ever seen, anyway, aftermarket forearms are made to fit the older 7 3/4" action slide tubes.

Remove your forearm from the slide tube if you have a slide tube and measure the tube from the back edge of the solid ring the bars are pinned to all the way forward to the front edge of the threads. No nut. If yours is 7 3/4", you're ok.

Just finished measuring a few foregrips here in the shop. The ATI AR-type foregrip will fit the shorter tube (it has a molded in line where you cut it to fit) as will their "standard" grip. Their older Thompson style won't, but it can be trimmed to fit, too. Speedfeed won't, but it's almost identical to the Mossy standard synthetic and Mav 88 corncob so just buy a Mav 88 grip if you want that look. Ram Line won't. Pachmayr won't.

Hope this helped.



May 21, 2009, 09:00 PM
Thanks for your help looks my tube is the smaller 6 and 5/8

Badger Arms
May 21, 2009, 09:57 PM
K850xxx is the cutoff from old to new.

Badger Arms
May 21, 2009, 10:29 PM
Hogue sells an adapter so their forend will fit on the new forend slides:

MidwayUSA has lots of options for forends. I don't think the Hogue product will work for anything but Hogue, but you never know.

July 3, 2009, 12:05 AM
Just recieved the hogue adapter from Midway USA looks like I am going to have to dremel out the inside of the stock for it ti fit but it will work eventually.

July 3, 2009, 01:41 AM
Didn't notice this or I would have said at the time....the Hogue adapter isn't for fitting their stock to shorter action slide tubes. That adapter was meant to mount *their oversized grip* to standard tubes. It's not the right size for the purpose you intended it to be used for. As you found out, it will take some good fitting to get it to work in that regard. I made a post comparing those very "adapters" a couple of years ago. I'll see if I can find it later.

Ok, I found it. This is cut and pasted from that earlier post:

""Ok, the Hogue adapter is exactly 1 5/8" long so it has the length....but there's a problem. If you're trying to install a ribbed synthetic forearm on your gun there's four narrow plastic rails inside the forearm that block the adapter thickness from fitting in. Those could be relieved with a Dremel sanding drum quite easily....*BUT*, the adapter runs out of threads on the tube before it socks the forearm down snug on the tube. A wooden forearm is even worse. The adapter is close to a half an inch too long for a standard Mossy wooden forearm. Again, you can Dremel the adapter about a quarter inch shorter....but it's still a trial and error job.

If you're handy with a Dremel, you can fit it nearly factory perfect. If you're not, it's not going to be much of a problem with it hidden inside the forearm and all. Me, I'd grab one and cut it in a heartbeat, but I have a great lathe. 7 5/8" forearms aren't rare, though. They pop up on gunbroker all the time and even Ebay now and then. You can spring for an adapter that takes an hour to fit or a $20 action tube that fits perfectly right off. Up to you, bud.""

Your best bet, read that as easiest, would have been to just go to gunbroker and pay $20 or so for the right sized action slide tube. They aren't rare by any means.



July 3, 2009, 12:47 PM
Thanks Rand that is exactly what I will be doing as I am putting the adapter on the ribbed forend. Hindsight is 20/20 and looking back I do wish I had purchased the longer forend but I got 12 bucks in the adapter so I guess I will make it work.

July 3, 2009, 06:10 PM
RM, just looking at that post of mine....and I'm not quite awake just yet so I may be wrong but it's worth mentioning....the adapter is only half threaded, so that means you'll need to remove about 1/4" from your slide tube, not the adapter. With your tube shortened and the longer adapter, you should get the size matched pretty well. Screw them both together outside your grip and then lay them beside your grip to get a rough measure on it before you proceed.


July 3, 2009, 11:08 PM
Thanks for the added info.

July 6, 2009, 01:52 PM
Hi chaps. Hope you all don't mind a Limey asking questions on your forum but finding answers in the UK isn't too easy?! :)

I have a Mossy 500A Serial Number T357*** and from reading RandKL's posts I have the Mav88 Forearm (bars being riveted directly to the plastic). I am ideally after replacing the forearm with a Hogue overmoulded or something similar but am a little unclear as how to go about it. I know I need to replace the action slide but can't work out if I need the 6 5/8" or the 7 3/4" action.

I'm guessing I need the 7 3/4" but can someone explain where I need to measure from and to on the Mav88 forearm?

Thanks all


July 7, 2009, 06:46 AM
You don't need to measure the Mav part, Jimmy. Those are all the same size. The size refers to the Mossy 500 slide tube that you'll replace your Mav forearm and action bars with.

On this slide tube, you'd measure it from the back edge of the thick steel ring the bars are riveted to all the way to the front edge of the threads on the tube. Really older Mossy's used 8 7/8" tubes. More modern ones used the 7 5/8" (7 3/4" to most folks). Those are the ones that most aftermarket forearms were designed to fit. Newer ones use an even shorter 6 1/2" tube. Some newer forearms, the ATI "standard", the ATI AR-type etc will both fot the short tubes. Just check your intended aftermarket forearm for a size and buy the right tube. If it doesn't list a size, it's a 7 5/8" pretty certainly.

If you need anything else, bud, let me know.

Be safe!


July 15, 2009, 01:53 PM
Thank you for clearing that up Richard. I'll get ordering the new goodies tonight; it's a shame I have to wait for parts to come from the US!

July 16, 2009, 01:58 AM
I read some where here that new model Mossberg 500 doesnt have slide tube assembly any comes with almost same forend assembly like Maverick 88.the action bars r attached directly to the forend.

September 12, 2009, 01:06 AM
I bought a 500A the other day. Pawn Shop.

The action tube is 4 3/4 inches long. The slide bars are 6 1/2 inches from the base of the tube to the ends.


Looks like they changed it again!!!

I think it'll be easier to just get a long one than go thru the adap trials....

Take care.

September 17, 2009, 01:20 PM
I have the new Mossberg 500 with the crappy Maverick 88 forend. Well I replaced it with a 7 5/8" Slide tube and nut, with the Hogue overmolded forend. With it installed everything works perfectly on the gun but when the action is open the forend doesn't sit flush like most forends do. You can see about a half inch of the slide bars. Check the Pic

Do I actually need the 6 1/2"? Like a said the gun is fully functioning and all other tolerances are perfect, just the gap in the pic. What you say?

September 17, 2009, 05:07 PM
H, your pic isn't coming up, bud. Can you try that again? If necessary, send me an email.

Ummm, skip that. It came up.

That's perfectly normal, Hypr. Different forearms fit to different lengths is all. The reason they've been going short like that is that a *lot* of folks use screw on side saddles these days to hold extra shells on the receiver and long forearms don't work with full sized sidesaddles. Slings are another thing. If you use a sling and the forearm hits the receiver, there's a chance the forearm can pinch the sling and in effect jam the pump motion. Yours is a perfectly normal Hogue. It's pretty close to the same length as the Mav 88 forearm, in fact.

The original Mossberg wood corncob overlapped the receiver by about two was great wood but really poor tactical!

The new ATI universal forearm doesn't even cover the action bar joint on the forearm tube. They made sure theirs works with all the add ons.


September 18, 2009, 03:01 AM
Ahh very good sir. Thank you for the info. Ya I just put a hogue tamer on their too the hogue forend/pistol grip feels awesome and very comfortable. I can't wait to go shoot it.

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