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Stock washer doesn’t fit..

PackFan12

Copper BB
I found a good deal on a set of oem wood furniture and an accompanying 6 3/4” slide tube assembly. However attempting to install it revealed that the stock washer that came with the synthetic stock does not fit down the shaft where the stock bolt goes. It’s just barely too large. The washer that came with the hogue stock and the washer from my mav88 are the exact same size so they don’t fit either.
I shot a customer service message to mossberg and they sent me a link to buy a new washer which will, again, likely not fit. Does the wood stock require a washer or just the stock bolt and lock washer? Did they fail to drill the shaft large enough? My google searches have come up blank as has the search function here. Thanks for any insights!
 
I found a good deal on a set of oem wood furniture and an accompanying 6 3/4” slide tube assembly. However attempting to install it revealed that the stock washer that came with the synthetic stock does not fit down the shaft where the stock bolt goes. It’s just barely too large. The washer that came with the hogue stock and the washer from my mav88 are the exact same size so they don’t fit either.
I shot a customer service message to mossberg and they sent me a link to buy a new washer which will, again, likely not fit. Does the wood stock require a washer or just the stock bolt and lock washer? Did they fail to drill the shaft large enough? My google searches have come up blank as has the search function here. Thanks for any insights!

Wood 500 butt stock bolt- 5 5/16"- long-5/16 18 thread. Measured from end of bolt to shoulder.
Uses a 7/16"thick lock washer.This is from a stock Mossberg butt stock.
I looked at my 1988 wood stock and that's what it measures without a flat washer.
After changing ANY stock I would remove the trigger assembly and look at the end of the stock bolt and make sure it is Not too long.
 
There are generally three types of "common" washers available for US hardware. The smallest is SAE (Society of Automotive Engineers) and the hole would be barely larger than the bolt size. The next and probably most common is USS (United States Steel) where the hole is about the next size up (ie: 5/16" would have a 3/8" hole) and the flange is a bit wider than SAE. Then there are what I call "fender" washers and they are quite wide with hole just a little bigger than the bolt.

Shown are 5/16" and 1/4" screws then 1/4" USS, SAE and fender washer, R-L. You probably need a 5/16" SAE washer for that stock bolt...

washers.jpg
 
If you can, use a flat washer with the lock washer. This will prevent the lock washer from biting into the wood. You can find one at your local hardware store. They are also east to modify if required.
 
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I always use a washer. Perhaps silly, but I figure it would somewhat protect the wood so the nut wouldn't dig down into it, perhaps maybe causing issue over time.

If your washer is too large of a diameter to slide into the hole, see if you can find a smaller one at the hardware store, or grind/file, sand the one you have down now. As Jmm14534 mentioned, it's not really a big task. You could likely get a whole pack of washers that would fit at walmart for .97 cents.

But as old mossy mentioned, just be sure that the bolt doesn't protrude too far into the rear of the receiver. If it does, you'll end up like I did and snap off the little tit on top of the trigger and the safety won't work anymore until you replace the trigger, which is a pain. I learned that lesson the very hard way.
 
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