Adding a RS Regulate GKR-9DY Handguard To A Zastava M77

Ok, so I planned to completely redo the M77 and keep the Battleworn wood for the future just in case. The first step was to swap out the wood handguards for a RS Regulate GKR-9DY. It’s a 9″ MLOK rail for Zastava AK-type rifles – this matters because a Zastava handguard is longer and a different shape than an AKM handguard.

Scot Hoskinson owns RS Regulate and is a meticulous engineer. His products are top notch and one thing I would tell you is to always read the instructions. He puts a lot of effort into documenting what you need to do so find the instructions and follow them.

Trust me – read and follow the instructions to install a RS Regulate handguard. Note the instruction sheet is for the old part number GKR-9Y. Scot revised the part number and it is now the GKR-9DY — same handguard but different part number.

Per the instructions in steps 3 and 4, I tapped the end cap into place. Note, you do need to test fit and make sure it will fit. You aren’t beating it into place with a ton of force. Mine went in without any filing needed but I did need to tap it to get it fully seated. You want the end cap to sit in the receiver firmly – not loose.

I don’t have photos of every step Scot lists, but I do want to mention step 5 – the front retainer set screws are backed out towards the receiver with the allen heads facing the rear. Once you have the front retainer in place and screwed to the handguard in step 10, you then tighten down the set screws to make everything nice and tight.

In all of his steps, be sure to follow the torque specifications and use blue loc-tite or your favorite medium strength thread locker. If you don’t, then the screws will risk coming loose and potentially falling out.

You can see the rifle’s handguard retainer is locked in place because the cam lever is rotated backwards. Looking down past the barrel you can see one of the two front retainer set screws waiting to be snugged down.

I used a long Bondhaus ball head allen key to reach in and tighten the set screws. Let me spare you some future grief – buy quality sets of allen wrenches that properly engage your fasteners. The cheap import keys are prone to poor fitment and/or rounding over the edges and both will mess up your fasteners.

I applied Blue Loc-Tite before I snugged down the set screws. I removed the residue with a shop towel.

The Gas Tube Cover

The RS Regulate handguards are the lower-half only. It’s up to you to decide if you want to run the wood or just what. In my case, I am using one of our Yugo/Zastava gas tube covers that is made from glass-fiber reinforced high-temp urethane. A Yugo gas tube cover is significantly longer than that of an AKM and are not interchangeable.

To remove it, rotate the locking lever on the rear sight base. Zastava is one of the makers that make that lever really tight. I use a large adjustable wrench’s jaws to hold the lever while I rotate it up. You can also use a hammer with plastic heads to tap the lever up. Once it is rotated, the rear of the tube closer to the receiver can be lifted up and the unit brought back just a tad to clear the front gas block. By the way, the bolt carrier must be removed or the long gas piston will be in the tube and block removal.

I didn’t get a picture of the gas tube with the wood before I removed it so we’ll just pick up here. This is one of our high-temp Yugo/Zastava gas tube covers. The spring clip is from the wood set and pops into the our cover to help provide tension and support. If you don’t have the clip, I would recommend buying one vs. skipping it. Check Apex Gun Parts, Robert RTG, Numrich, Centerfire, etc.

The spring clip just presses into the pocket molded foir it in the cover.

I like to use a vise to hold the forged end of the gas tube. DO NOT try and clamp the thing circular end or you will crush it. The vise you see has smooth jaws and will not hurt the forging – if your vise has aggressive jaws to hold material, use something to protect the gas tube like jaw covers, pieces of wood, etc. In this photo, the cover is fully rotated into position. You may find it easier to rotate your cover to the left or to the right when it comes to installation or removal. If it will not turn, carefully inspect why and remove a bit of material as needed with a file, Don’t rush – you want a firm fit and for it to look good.

Years ago, I did do a blog post with more instructions and links to videos. Please click here if you want to read it.

End Result

Summary

RS Regulate makes some great lower handguards for a variety of AKs including for the Yugo/Zastava M70 and M77s. It takes a little bit of effort to install and is very much worth it. You can optionally use your wood gas tube cover or buy one of our polymer units.

Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.

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