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IZ-433 Magwell and Magazine Fitting

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The magwell has some residual rough areas from the injection molding process. Sanding these down helps improve smooth mag insertion and removal. The main area to be sanded smooth is at the inside front of the magwell. The inside rear of the magwell can also be sanded, but mine did not require any. However, do not sand the inside sides of the magwell, as these help stabilize the magazine while in the firearm.





The 8 round magazines from Legion USA Inc worked perfectly without any fitting, but the 8 rounders I received from RusMilitary would not lock into the firearm. On these magazines the bump on the rear of the magazine needed to be filed down until lockup occurred. File a little bit at a time and check frequently to obtain lockup and maintain a tight fit.





I was surprised how little modification is need to obtain great lockup with AGP rock-and-lock magazines. If I would have known this first, I might not even have purchased any Izzy 8 rounders. There are several steps fitting AGP mags.


1st step - Front Lug: Mill or file the front lug off of the magazine. I found that using a Magnetic Polycast Protractor allowed consistent results. I simply set the magazine in the mill with the protractor resting up against the second screw bump at 25* and milled down the front lug until the thickness of the magazine lip was 3mm thick.







2nd step - First Screw: Mill or file down the first screw bump to the exact height of the screw head. This time I set the magazine in the mill with the protractor resting up against the second screw bump at 16* and milled down the first screw bump until the screw head. After this step the magazine should fit perfectly in the magwell. The only other thing to do is deal with the LRBHO, because at this point your bolt carrier will be locked back as a result of hitting the top of the AGP magazine.




3rd step - Release Bolt Carrier: Remove necessary material from the top of the magazine with a Exacto knife to allow the LRBHO to release the bolt carrier when the AGP magazine is inserted into the magazine. Insert the magazine into the firearm and remove only what is necessary.




4th step - LRBHO: Design and implement some way to activate the LRBHO. I spent 5 minutes with scissors, sheet metal, and double stick tape to make the temporary fix seen in the pictures. This was just a temporary fix, and I do not recommend using such thin material or double stick tape. Do what you think is best.





Edited by lokmeup
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Tried modifying a 12 round SGM magazine I picked up today using the information I found in the forums. Couldn't find step by step instructions for the SGM mag mod for iz-433 so I just muddled my way through with what I could find. This post helped out a great deal so I'm gonna add a little to it.

First I cut off the front lug with a utility knife (all the posts I've seen seem to agree on this step).

Then I filed down the front lip of the magazine where the lug was until it was close to flush with the rest of the magazine body (many of the posts mentioned straightening the front of the magazine, but did not go into specifics)

Modified SGM magazine for iz-433 magwell

Modified SGM magazine for iz-433 magwell

Modified SGM magazine for iz-433 magwell

The magazine fits perfectly. There is no wobble and seems to load fine. I've cycled several rounds through the magazine and have had no problems with it yet. Next step is to get the LRBHO working with this magazine and test it out on the range.

Edited by Ashur
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