FAL/Sten mag 9mm conversion kit

Instructions for the installation of the Sten mag conversion parts

This is a very easy kit that is specifically designed for the do-it-yourselfer who has a minimal amount of tools and skills. We have included instructions that do not use any fancy tools. 


Step 1, install the gas block onto the barrel. This is very easy for the most part. Just slip the gas block onto the barrel and then using a piece of wood and an hammer pound it on until the holes align with the groves in the barrel. Do not worry about weather it is aligned with the rear sight at this time.

Use a block of wood to protect the front sight block from the hammer. This shows the complete unit and how it goes together.


Step 2, install the barrel. Remember to first install the hand guard ring. The installation of the barrel is easy, just turn it until it will go no further, you may want to use a barrel vise and receiver wrench to make sure it is on nice and tight. You can make a barrel vise out of wood blocks (this does not normally work with other rifles but will work in this application). To make a barrel vise out of wood blocks, use a 4"*4" block of wood and drill a 1" hole through the middle. Now split the block down the middle. You now have some good vise jaws, so insert them into a vise, wrap the barrel in a paper towel for maximum grip and then insert the barrel into the wood vise jaws and tighten as tight as you can get. Now you can screw the receiver on and get it very tight. This will help insure a good headspace. Once you get the barrel on, use a spanner wrench( the M16 stock tool will work and it usually $5 or less) and turn the barrel lock ring so it is nice and tight. Once it is tight, mark the top were the gas nut is and then remove the ring and sand, file or mill a flat area so the gas nut will go on all the way.

This shows the spanner wrench used to tighten the hand guard spacer ring. Note the tape used on the spanner wrench to keep it from scratching parts. Once the hand guard spacer ring is on all the way, mark the top area and then remove the ring and sand or mill the area flat.  The ring has had the area sanded flat and has been re-installed. There is now enough room for the gas nut to be installed without it hitting the ring. Not it has not yet been tightend and the amount removed will vary with different receiver types.


Step 3, align the gas block. You can use a wrench and something to protect the gas block from being dented and just turn the block until it is aligned. Once you have it were you want it use some high grade epoxy and put it in the front hole. Let it dry over night and that block will be on there. For those of you who want to pin it, use a mill to drill a hole through the block and then you can pin it.

Missing Missing


Step 4, Install the adapter. This is very easy, just turn the receiver upside down, insert the adapter and them push it in all the way. Now remove it and scrape away any plastic that was shaved off. Now re-install the adapter and once it is nearly all the way in use a block of wood and tap it in the rest of the way until the original mag catch snaps back. If you can not get the original mag catch to snap all the way back and lock in you will need to remove the plastic adapter and shave a little amount of plastic off and retry the procedure. You may also need to use a Dremmel to correct the radius on the side of the mag well so the adapter will go in all the way. Don't forget to install a bolt hold open device, you will have to remove the pin sticking out the side. 

The adapter has been installed most of the way, note the original mag catch is still depressed and the adapter is not locked in. Use a block of wood and lightly tap the adapter in all the way. You should see the original mag catch move. This adapter has been installed correctly and is locked in, Note the original mag catch is fully rearward.


Step 5, insert the bolt and check for clearance. Slide the bolt back and forth to make sure it is not hitting anything. You may need to use the Dremmel or similar tool to lower the original ejector a tiny amount.

Missing Missing

Step 6, modify the mags. We are going to have a jig that will show were to make the cut on the rear of the mag, for the mag catch to work. You can make the slot cut with a mill or a Dremmel. Once you have made a slot on the mag, check the mag to make sure it will go into the mag well and the catch will lock it in. Now slide the bolt foreword to make sure the bolt does not hit any part of the magazine. If it does not you are ready to proceed.

Missing Missing Missing


Step 7, add the top cover and recoil spring. Don't forget to install the buffer. 


Step 8, Testing. Now with the gun pointed in a safe direction, insert the magazine with a dummy round in it and then pull the cocking knob all the way back and let it slide foreword. It should cycle the round. Now pull the cocking knob back and the round should eject out. You are now ready to try live fire testing, first insert only 1 round into the magazine and proceed to fire it. Now inspect the ejected case for blown primers and split cases. If they look ok, then load 2 rounds into a magazine. Fire the first one and then remove the second from the chamber. Inspect the 2nd round, you are mainly interested in the primer. Look at the primer and make sure the firing pin did not leave any impression on it. If it did not then it is safe to shoot some more. Now load up 3 rounds into the magazine and fire all three. If you did not have any problems you are ready to enjoy your new rifle.


The End