January 2011: I have not been keeping up with the specifics of this FAQ for quite a while. There are now so many different types of AKs on the market and the SARs are a rarity. Please keep in mind that was written in 2003 and that your specific AK may be completely different; there's just no way to know with specificity what exactly is going on with the front of your barrel without checking.


I've posted this on another "ahem" AK website, and thought it might come in useful here too.... I'll start the general FAQ, and everyone else can chime in with their corrections/additions/personal anecdotes.

1) Diameter of barrel

Most SAR-1 and SAR-2 rifle barrels are 14mm diameter, although it does vary slightly from rifle to rifle. SAR-3 rifles usually have 1/2" diameter barrels. Non-standard sizes will have to improvise. I have recently heard of and finally seen with my own eyes that the diameter of some SAR's can vary from the FSB forward. At a recent gun show, I saw 4 laminated SAR-1's laying side-by-side. One of those had a noticeably thinner barrel from the FSB forward. This barrel will be too thin to thread.

2) Type of muzzle brake

The two most common variants are the "slant" brake and the AK-74 style muzzle brake. Figure out which one looks better to you. SAR-1's look most authentic with the slant brake, SAR-2's mate up with the AK-74 brake. There are AK-74 style brakes which will work for an SAR-1 also.

AK brakes come in different internal thread diameters and and thread pitches. Common are 14mmx1 LH (Most common, used by slant brakes, aftermarket AK-74 "style" brakes, and polish Tantals), 22mmx1.5 LH (unique to Romanian AK-74 muzzle brakes), and 24mmx1.5 LH (AK-74 brake).

I don't know if there are any "genuine" AK74-style brakes in 5.45 caliber which thread on 14mmx1LH barrels. This would be important to someone with a SAR-2 trying to keep the correct AK74 "look" by threading the barrel. There is a smaller US made brake, but its external diameter is quite a bit smaller than the real thing and doesn't look authentic.

3) Attachment to barrel

Muzzle brakes are available in many different styles. The most common are ways to attach them are:

(a) Set screws

The cheapest, but not the sturdiest way to go the muzzle brake route. The internal bore of the muzzle brake should slip over the barrel with a tight fit, or you'll have to shim it. Either way, it is highly recommended that the barrel be dimpled under the set screws. Dimpling is accomplished by carefully drilling into the barrel just deep enough to leave a little crater for the set screw to "bite" into.

To make a muzzle brake with slip-fit properties, you can either buy a brake which has no threads and fits tight, or you can use a Dremel tool to grind off the threads. in the latter case, you'll have to make sure the brake slips on concentric to the bore. You can drill and tap the brake for any number of set screws yourself if you have this ability. If all else fails, you could probably still have someone weld it on for you so it stays put.

Dynasystems can make brakes with custom internal bores and set screws, and they also have an adapter which has set screws to attach to the barrel, and has 14mmx1LH threads so that you can thread a muzzle brake to the adapter.

Set screw muzzle brakes are the cheapest way to do it (usually), but they have the problem that the gases they redirect also cause them to slip off the barrel and fling them down the range, especially with the 7.62 caliber guns. Read the Dynasystems page where they talk about the thread adapter for more info. The barrel dimpling method is supposed to work pretty good though.

(b) Threaded barrel

SAR-1's do not have threaded barrels. WASR's do no have threaded barrels but a muzzle nut which is pressed on and welded. Cutting off the muzzle nut usually won't work as witnessed by several people on the board. Do a search on the board to find out what the problems are. CORRECTION: There's no way to really determine what your WASR's muzzle might look like; it probably depends on what the Century monkeys had laying on their desk that day. I'll avoid making general commentaries; you'll just have to inspect it and see what you get.

A lot of gunsmiths won't try threading the barrel. They're probably thinking of chucking up the rifle on their lathe, and that's not easy. The tool best used for this is something you can do at home. Dynasystems sells a muzzle threading kit, which is also making its way around this board for rent. With this tool, you can thread your barrel to 14mmx1LH, although it's available in several other sizes also. SAR-3's usually come in 1/2" diameter barrels, which is also common with AR-15's. Those are usually threaded 28tpi. The threading kit costs $60 if you purchase it, while rental fees are usually in the $10-20 range.

It may sound scary to do that to your rifle, but it's fairly easy. Just be careful and follow the instructions. The die cuts the barrel fairly easily. If you're curious, here's what the instructions consist of: preciseinnovationsllc.com/GunFile/ThrInstr.html

The problem is that now you have a threaded barrel, which won't make the BATF happy if you live in a state with its own AWB. You'll have to attach the brake in such a way as to make it permanent, at least as far as the ATF is concerned. More on that later. The rest of you rejoice - you're good to go.

Once the barrel is threaded, you can directly thread on a 14x1LH threaded brake. You can also get an adapter bushing which has 14mm internal threads and 22mm or 24mm external threads to allow threading on the larger brakes, which will in turn allow you to attach AK74 brakes.

If you have a threaded barrel, you will also want to install the dentent spring and plunger if yours is missing. This will prevent your muzzle brake from twisting off. All AK muzzle brakes (if I'm not mistaken) have a notch which will index on the plunger sticking out of the FSB. You can order something like this set from Globaltrades or you can make your own out of a small piece of steel rod and a spring of the proper length. If you check this picture on K-Vars website, you can clearly see the hole in the front of the FSB just above the threads where the plunger and spring need to be installed. To do that, you will need to drive out the retaining ping enough to allow you to slip the plunger into place. The plunger has a notch ground out, which will keep it in place when the retaining pin is reinstalled. These pins are difficult to remove; they need to be hit quite hard, and with a strong pin punch. It's not necessary to completely remove the pin. Make sure your FSB is properly supported so that you don't twist it on the barrel. Tapping the pin back in is quite easy; simply drive it flush.

(c) Threaded FSB

This is covered by linx310's website: linx310.nothingbutguns.com/threadinstall.htm

Also check out that website for a home-made adapter. Personally, I find that too much of a hassle, but it's certainly innovative.

(d) MAK-90 brakes

These are available cheap, like $10 I believe, to fit MAK-90's. The problem with these is that they are supposed to be pinned on the FSB of MAK-90's, and the pins don't work for SAR rifles, and the barrel on the SAR's is too small. Nevertheless, several people have made it work, going the route on slip-on brakes with shims to widen the barrel diameter. You will also have to use a Dremel tool to cut a slot in the bottom of the brake to allow it to fit around the cleaning rod. Here's a thread with a successful conversion: www.gunsnet.net/forums/showthread.php?s=&threadid=80816

4) Legal issues

(a) General disclaimer

Obviously I'm not reposible for anything legal, so all of this is done at your own risk.

(b) Parts count

To stay legal in the ever-popular parts count sham, you'll have to replace a foreign made part with a US made part on your rifle if you add a foreign-made brake. If you add a US brake, you're fine.

(c) Legal attachment of muzzle brakes to threaded barrels

The paragraph below is not needed in those states where the AWB has expired. Please make sure you check your local laws before leaving a threaded barrel exposed.
Since having a threaded barrel will incite you to obtain silencers and go on shooting rampages, you'll have to "permanently" attach your brake to the BATF's satisfaction. This can be done by several methods: Spot welding, which is kind of ugly and will discolor the metal due to the temperatures involved, and is somewhat permanent depending on how its welded. The second is to use high-temp (1100deg) silver solder. This will also discolor the metal, but has the advantage that it can be easily reversed if the AWB sunsets. If you have the right equipment, you could do it yourself. The third is a blind pin drilled though the brake and into the threads of the barrel which is welded over and ground flush. The re-bluing can be easily done at home and if the AWB sunsets, you could cut off the brake. This method is fairly cheap - I paid $20 at a local gunsmith.

The correct way to attach brakes is via a plunger/spring which fit into the FSB. The are available from KVAR and Global Trades among others. You need to drift out the pin closest to the muzzle on the FSB. These pins are very tough amd need a pretty good pounding to get them started. DO not use a long pin punch for this method. A nail set worked for me. Once the pin has budged, you can usually use a pin punch to drift it out a little further. It doesn't have to be completely removed, just drifted out far enough to allow the spring and plunger to be inserted. I used a Bulgarian set, and the plunger was a little too long, so I had to grind it down about 1/4". Be careful to not take off too much material such that the pin won't be held in by the FSB pin anymore. When you look at the plunger pin, you'll know what I mean.

More information on 22mm threaded barrels/FSB, please refer to www.gunsnet.net/forums/showthread.php?s=&threadid=59131

5) Sources

Here are some sources of muzzle brakes and various parts:
www.dynasystems-ltd.com
www.globaltrades.com
www.krebscustom.com/CustomParts.html

And some others. I'll let the community fill in. Please add to/correct this information to keep it current.

Originally Posted By Zhukov: Obviously I'm not reposible for anything legal, so all of this is done at your own risk. (b) Parts count To stay legal in the ever-popular parts count sham, you'll have to replace a foreign made part with a US made part on your rifle if you add a foreign-made brake.

Zhukov,
I'm a newbie that just bought a Romanian SAR2. I'm wondering about the guidline above. I'd like to keep this baby as "authentic" looking as possible. Seeing as that I'd like to replace the wood furniture, trigger group, and sights (not sure with what) anyway, can I then added a foreign made brake?

Thanks for the help.

EDIT: By "authentic" I don't mean Romanian. If it looked like something a Russian Spetnaz soldier might carry (if not issued an AN-94 heheh) that would be pretty cool. Perhaps black furniture and a red-dot sight or whatever they might use.

Also, thanks for the great info!

(d) MAK-90 brakes These are available cheap, like $10 I believe, to fit MAK-90's. The problem with these is that they are supposed to be pinned on the FSB of MAK-90's, and the pins don't work for SAR rifles, and the barrel on the SAR's is too small. Nevertheless, several people have made it work, going the route on slip-on brakes with shims to widen the barrel diameter. You will also have to use a Dremel tool to cut a slot in the bottom of the brake to allow it to fit around the cleaning rod. Here's a thread with a successful conversion: www.gunsnet.net/forums/showthread.php?s=&threadid=80816

I was thinking about having my machinist workup about 25 or so of these with bushing material included in a kit for $25. They are AK74 type brakes and would require finish fitting by yourselves or a gunsmith. The cuts to fit the Romanian AK's SAR-1 and WASR-10 would be made. It would require the bushing, pinning and final inspection to make it ready. Look over the above thread and if anyone is interested let me know.
thanks

Well, after running back and forth about what kind of muzzle brake to get, I went with a -74 style MAK-90 brake for my WASR-10 from Tapco ($19.99 US Made). I simply cut out a notch for the cleaning rod with a dremel and it fit on very good. Then I lined it up straight (it was already really straight because of the notches) and MIG welded the top and sides of the front sight block to the brake. If you know how to weld or know a friend who does, this is a very easy way to do it. About 10 minutes, $20, and no running to the store for shims. Here's a pic of the completed product.

Originally Posted By Hatchet36: Thank you Zhukov! The info was very helpful. Now that the AWB is gone do you plan to make an update to help those who are confussed? Maybe mention that wjm@gte.net is one of the guys out there who is renting a threading kit?

Already done, I think....

I haven't added WJM as the threading kit rental guy, but I suppose you just did.

So if I have a WASR with a welded muzzle nut, I'm shit out of luck if I want to thread a brake on???

I was looking into the muzzle threading kit by Dynasystems a while back for my SAR-1, but then I heard that threading your own barrel with one of these threading kits decreases the accuracy of the rifle. The source that I was talking to said that the preferred method was to have the threads cut on a lathe.

Has anyone heard this? The muzzle threading kits sound great, but I've put the idea to the back burner for now. Woud someone please offer some clarification on this. Thanks.

Thanks Zhukov. As a matter of fact, I did hear this from a gunsmith. I think I may have to get one of these kits next month when I can afford it. It should work for both my SAR-1 and my Norinco SKS, both in 7.72 x 39mm.

If you order all the stuff from brownells how much does it cost? What items do you need? Do you have to remove the front sight post? I have a WASR10 I am planning to thread. Any suggestions would help.

Originally Posted By Zhukov: (b) Threaded barrel SAR-1's do not have threaded barrels. WASR's do no have threaded barrels but a muzzle nut which is pressed on and welded. Cutting off the muzzle nut usually won't work as witnessed by several people on the board. Do a search on the board to find out what the problems are.

Just to let you know that's not allways true. I just got my Romanian AK and I cut the single tackweld off and found the barrel to be threaded with lefthand threads.

I've seen a slant break on some sites labeled as a flash hider. I looked this up this here http://en.wikipedia.org/wiki/Muzzle_break and found out that a muzzle break increases the report of the shot as well as the flash. Is that accurate? I imagine it is possible to take a muzzle break off a wasr-10 and replace it with a flash hider? My wasr-10 also had a threaded barrel. Thanks for the faq!

I have an older WASR with a welded nut. It takes some careful work to cut the welds, I used a dremel and then tapped the nut off with a hammer and screwdriver. My barrel wasn't threaded, but instead, was turned down to a smaller diameter and could not be threaded. It was also longer than the typical muzzle length.

I cut the barrel 1/8" shorter with my dremel, cleaned it up with a file, and then crowned it with a carriage bolt in a hand drill using valve lapping grease.

Then, I slid on the slant brake, and drilled through the brake into the barrel just enough to leave a small dimple in the barrel. I tapped the hole in the break and put in a set screw. I JB Welded the whole thing, tightened it down, and then ground the set screw flush with the brake and painted it black.

When it was completed it looks correct. I also added a detent pin, even though it's non functioning.

Looks perfect :)

most newer WASRs either have a threaded barrel with a nut welded on, or no nut at all.

I know this has probably been asked a couple times, but how do I know if my SAR 1 barrel has enough meat on it to be threaded?
Does anyone know how big the barrel needs to be? Or a link to the info

Thanks