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Mods & Upgrades pt1- receiver, button, sling

Discussion in 'Mossberg SA-20' started by sneektip, Jun 4, 2018.

  1. sneektip

    sneektip .22LR

    This is part 1 of 2 of the Mods & Upgrades part of my review (Part 2/3 total?). I wanted to do this in one big post, but found out about the 10 pic max per post, so I'm splitting it up. I wanted to give back to the community with an in-depth write up, in thanks for all that others have taken time to share. I've done a lot to this gun and I owe a big THANK YOU to the wonderful members here. Some of the things I will go over in this post have already been covered elsewhere on this forum, and that's because this forum is where I gained much of my starting point knowledge.
    The first addition was a Choate mag extension. After arguing with a CS person at Choate about the definition of "+2", I was able to clip the spring enough to suff 7 rounds of 2.75" shells in the magazine. So she is now a 7+1 gun.
    As for the work I've done, we'll start with the action.
    I polished the chamber with a 12ga brass brush wrapped in 0000 steel wool. Chucked in a drill, I spent about 10 minutes running it at high speed. Then the same process with a 12ga mop and polishing compound. It was a bit of a bugger cleaning the compound out of the chamber afterward. Maybe a better quality compound would have been easier to clean up? I just used what I had on hand.
    Then on to polishing everything else. Anything that touches anything. But you tinkerers already know about all that, so won't go into detail here.
    My particular specimen seemed to be grumpier than most when it came to running lighter, or even "standard" 1oz loads, so I opened up the gas ports just a smidge. Used a drill bit and followed up with fine sandpaper rolled tiny enough to pass through the ports. I wasn't surprised to find a couple small burrs on the inside of the ports from the factory.
    Then I decided to follow another member's lead and mill a feed ramp into the lower part of the receiver. And while I was in there, decided to open the inside walls to allow greater clearance for my thumb knuckle while shoving in shells.
    Not an easy spot to photograph, but you get the idea. I used a Dremel with an 1/8" endmill bit.
    And here are the receivers inside walls:
    IMG_7103.JPG It's cut lopsided because the roll pin limited how much material I could take off that side.
    Next came the sling loops. I wanted to duplicate the GG&G hardware I’ve seen on other, more popular shotguns. I created front and rear sling loops from flat aluminum sheet stock to compliment my sling of choice, a Magpul MS3. The rear was simple enough, but the front took some planning, some executing, and then a bit of hand finishing to get the fit just perfect. The factory sling studs were removed.
    IMG_7008.JPG IMG_7009.JPG
    The rear is attached with two small bolts, and lock nuts inside the stock. The front is just friction fit by the mag extension. I was concerned about the lost use of the spring loaded detent here, but have not had issue with the extension tube backing off during use.
    I still have my drawn plans with dimensions, if anyone is interested in making a front attachment point of their own. I've also toyed with the idea of doing one with a small plate that a picatinny section could be bolted to on the opposite side for mounting a light. But that's a project for another day.

    As for the bolt release button, I wanted something big and easy. I made a new button extension from thicker aluminum bar stock.
    I filed a flat, drilled & tapped the factory button, and countersunk the screw hole in the new button extension. The factory button pivots on an angle inside the receiver, depending on the status of the action. So plan accordingly. Now with the extension installed, when my action is closed, the new button sits straight, parallel with the side of the receiver, and out of the way. But when the action is open, i.e. locked back & empty, the button sits at an outward angle to be easy to find, even while wearing gloves.
    I used some vibratite on the screw threads. On the mating surfaces of the countersunk button and underneath the screw head, I roughed them up with sandpaper and applied red locktite to prevent the extension from rotating on the factory button. No problems so far.
    I’m currently having issues uploading the photos to the next section of review. Apparently the files are too large. I’ll have to get this figured out before I can post the last chapter of my review.
    Last edited: Jun 11, 2018

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