Other than the threads, is there something about the AK...

este · Post by **este** » Thu Sep 03, 2009 3:59 am

that makes it a poor suppressor host?

If you had a perfectly concentric barrel, would it suppress well? I'm only looking at subsonic speeds (weird project).

CKOD · Post by **CKOD** » Thu Sep 03, 2009 6:11 am

este wrote:that makes it a poor suppressor host?

If you had a perfectly concentric barrel, would it suppress well? I'm only looking at subsonic speeds (weird project).

ArrevaloSocom knows all about silencers on AK's ask him about baffle strikes

jjgow · Post by **jjgow** » Thu Sep 03, 2009 8:45 am

Apparently, the gas vents in the tube cause it to be louder than it should. At subsonic speeds, I'm not sure if the gas would even get to the vents (I don't own an AK, so I'm not sure exactly where the vents are located compared with the piston). It'll likely be much quieter than supersonic, and I'm sure you could block the vents if you were so inclined.

Cardi · Post by **Cardi** » Thu Sep 03, 2009 10:48 am

The vents are located just forward of the upper handguard and can be seen on both sides as small half circles cut into both the handguard tube and the portion attached to the barrel, forming a complete circle when the rifle is assembled. Therefore, if you wanted to block the holes with epoxy, you might end up permanently attaching both pieces. You can see the holes in the far right of this picture:
http://www.ultimak.com/AKStockR&R/AKR&RFig8.jpg
Since these two pieces provide such a loose seal, you might have to seal the whole connection to get good results.

este · Post by **este** » Thu Sep 03, 2009 12:29 pm

jjgow wrote:Apparently, the gas vents in the tube cause it to be louder than it should. At subsonic speeds, I'm not sure if the gas would even get to the vents (I don't own an AK, so I'm not sure exactly where the vents are located compared with the piston). It'll likely be much quieter than supersonic, and I'm sure you could block the vents if you were so inclined.

Blocking vents never seems like a good idea

I guess at subsonic I could understand how it might be less, but if the round is enough to cycle the action it should be enough to get into and then out of the vents.

If it were a problem, and the vents were sealed, you'd be venting the gas back into the barrel through either the action or the muzzle/silencer. I wondering that is such a good idea?

Dweezil · Post by **Dweezil** » Thu Sep 03, 2009 5:51 pm

Couldn't you just start with a Yugo and turn off the gas valve? Basically, make it a straight pull bolt action?

You may also want to go on the Finnish gun site guns.connect.fi and look at some of the BR-Tuote suppressors for the AK. They use large volume suppressors, with simple baffles that don't create a lot of back pressure. Would be a good basis for a Form 1 project.

Pat M · Post by **Pat M** » Thu Sep 03, 2009 5:57 pm

couldn't you just make a sleeve that slides over the vent tube (if you're running a reduced pressure load)

este · Post by **este** » Thu Sep 03, 2009 6:41 pm

Pat M wrote:couldn't you just make a sleeve that slides over the vent tube (if you're running a reduced pressure load)

I don't even know it's a problem yet. I've only heard people suggesting the possibility of.

YugoRPK · Post by **YugoRPK** » Thu Sep 03, 2009 7:46 pm

There is no thread shoulder. The threads stop at the front sight and the front sight indexes the silencer. If the threads are a bit loose the silencer will not be square against the bore and you're likely to get baffle strikes. The threads always get blamed for being not bore cencentric but probably most times its the front sight that is the source of the problem. Its not a precision machine surface thats 90 degrees to the bore center line. Most times its just a cruddy casting from a cruddy communist foundry.

este · Post by **este** » Thu Sep 03, 2009 8:52 pm

Yugo, Thank You.

That makes perfect sense. It also explains why I've seen some AKs with silencers (never heard though) and others say it's a terrible idea. It's not impossible to correct a missing shoulder.

So... If one went into a custom build with the intention of using a custom barrel with a proper shoulder of course. It shouldn't really be an issue.

However, I'm still curious to know if the action, gas system, or other make more than an acceptable amount of noise.

YugoRPK · Post by **YugoRPK** » Thu Sep 03, 2009 10:34 pm

This one had a 2 point mount to avoid baffle strikes. Arsenal USA sells a model with a similar barrel setup the one in this video but I built a longer gas system on this one so the barrel only extends 2 1/2 inches past the sight.

http://www.arsenalinc.com/slr107cr.htm

http://www.youtube.com/watch?v=YeKquXp8 ... annel_page

este · Post by **este** » Fri Sep 04, 2009 8:38 pm

YugoRPK wrote:This one had a 2 point mount to avoid baffle strikes. Arsenal USA sells a model with a similar barrel setup the one in this video but I built a longer gas system on this one so the barrel only extends 2 1/2 inches past the sight.

http://www.arsenalinc.com/slr107cr.htm

http://www.youtube.com/watch?v=YeKquXp8 ... annel_page

Ever gotten one or seen one cycle with subsonic?

I researched adjustable gas blocks for AKs today, nothing except for one that looks a little heavy and a little crude... Perfect for an AK, but maybe no my specific requirements.

YugoRPK · Post by **YugoRPK** » Fri Sep 04, 2009 10:28 pm

este wrote:
YugoRPK wrote:This one had a 2 point mount to avoid baffle strikes. Arsenal USA sells a model with a similar barrel setup the one in this video but I built a longer gas system on this one so the barrel only extends 2 1/2 inches past the sight.

http://www.arsenalinc.com/slr107cr.htm

http://www.youtube.com/watch?v=YeKquXp8 ... annel_page
Ever gotten one or seen one cycle with subsonic?

I researched adjustable gas blocks for AKs today, nothing except for one that looks a little heavy and a little crude... Perfect for an AK, but maybe no my specific requirements.

Ive heard of people getting one to cycle but I never have. Even clearly transonic won't cycle. I suppose I could use a lighter spring but Ive never tried it. They do partially cycle but not enough to eject and chamber a new round.

este · Post by **este** » Fri Sep 04, 2009 11:26 pm

Any changes to the gas port diameter ?

This is the block I'm considering. Seems to be the only game in town. It looks heavy but I think I could at least use it as a starting point if I wanted something different.

I wonder if the AK-100 series' 90Âº port would allow any more than the 135Âº of the traditional AK? Wish I knew more about port diameter as I almost definitely see a suppressed AK in my future.

I think I want a noveski switch block for an AK... I'll start holding my breath right... now.

YugoRPK · Post by **YugoRPK** » Fri Sep 04, 2009 11:41 pm

Mine has a 90 degree gas port with a 1/8" gas port. I dont get any gas in the face so I'm not sure that changing to a switched gas bock will do much besides allow the gas system to completely turn off . With subsonics I'm not really sure it could be any quieter. Full power ammo its loud but no louder than any other centerfire can bun firing full power ammo.

ArevaloSOCOM · Post by **ArevaloSOCOM** » Sat Sep 05, 2009 12:10 am

CKOD wrote:
este wrote:that makes it a poor suppressor host?

If you had a perfectly concentric barrel, would it suppress well? I'm only looking at subsonic speeds (weird project).
ArrevaloSocom knows all about silencers on AK's ask him about baffle strikes

For pete's sake.......lol

I'll just say this. Make sure the freaking barrel is concetric and don't be a rush to try out a suppressed AK until it is. I had MASSIVE baffle strikes from a Saiga 308, MASSIVE.

FWIW I have a Saiga AK47, had a smith who does good thread jobs check the bore this time and it's good to go. 1/2 X 28.

I, beleieve it or not plan to suppress this one, but this time it will be done right instead of russing into it.

Expensive lesson learned!

este · Post by **este** » Sat Sep 05, 2009 12:20 am

Your right, switched wouldn't help... I'm going to need an adjustable one. That's all there is to it. The people that make that DEZ one seem to be pushing it on every forum everywhere... I'll bite I guess.

With a tight bore suppressor (monolithic I'm thinking) and an adjustable block I would think that there would be enough pressure to operate an AK action... but, I'm not sure because I can't seem to find any record of it ever being done.

I have a barrel blank and a profile drawing. I'm thinking .75 fluted or .600 (whatever the heaviest AK was). I know step one of trying to make an AK accurate is to buy an AR but... I'm apparently I have deep rooted issues that manifest in a desire to take on difficult projects.

YugoRPK · Post by **YugoRPK** » Sat Sep 05, 2009 12:39 am

este wrote:Your right, switched wouldn't help... I'm going to need an adjustable one. That's all there is to it. The people that make that DEZ one seem to be pushing it on every forum everywhere... I'll bite I guess.

With a tight bore suppressor (monolithic I'm thinking) and an adjustable block I would think that there would be enough pressure to operate an AK action... but, I'm not sure because I can't seem to find any record of it ever being done.

I have a barrel blank and a profile drawing. I'm thinking .75 fluted or .600 (whatever the heaviest AK was). I know step one of trying to make an AK accurate is to buy an AR but... I'm apparently I have deep rooted issues that manifest in a desire to take on difficult projects.

I know one guy who regularly knocks out sub MOA groups with an AK pistol. His secret is the ammo and optics. Biggest POS with the AK are the sights. Put a solid scope mount and a decent scope on it and use good hand loads and its as accurate as any other gun even without going overboard on barrel diameter.

PTK · Post by **PTK** » Sun Sep 06, 2009 6:05 pm

Back when I had my 762SD, I drilled and tapped the QD mount for 14-1LH. It worked, no baffle strikes. It was a real PITA to shim concentric, though - the gas block is the major issue.

FWIW, that 17-4PH steel is a bitch and a half to machine.

kernelkrink · Post by **kernelkrink** » Mon Sep 14, 2009 6:10 pm

Regarding the gas vents on the AK, different styles exist. The original milled AK47 used a series of holes drilled in the gas tube a bit behind where it mounts to the gas block. When the Warsaw Pact nations went to the stamped AKM design they relocated them to the gasblock/tube interface like is commonly seen today. However, the Chinese never received the AKM tech package and instead went with a thicker stamped receiver and left evrything else basically old school AK47. Prebans and MAK90s have the drilled holes in the tube. You can take a Chinese rifle and add a Euro AKM tube, no vent holes. You can also replace the Euro AKM gas block with an earlier milled style, no vents. Since the gas tube is larger than the piston any excess gas will now be shot past the piston, down the tube and out the rear sight base and receiver.

BTW, the gas vents do nothing regarding functioning, by the time the gas reaches them the piston has already left the gasblock and the gas is just dumped overboard at that point to keep it out of the action.

A custom diameter piston that fits the gasblock tighter than normal would help with cycling low pressure rounds, the factory clearances are designed for reliability in dirt not max efficiency. On the angled gasblocks it is easy to make an adjustable gasport. Just drill the port hole oversize then tap the gasblock port for a setscrew. Drill out a set of setscrews in different diameters then try them out for function. Not as easy as turning an adjustment screw but costs essentially nothing.

este · Post by **este** » Tue Sep 15, 2009 3:13 am

kernelkrink wrote:Since the gas tube is larger than the piston any excess gas will now be shot past the piston, down the tube and out the rear sight base and receiver.

... Right into my eye! ...

Just kidding. Thank you, that's very good info! I think I'm going to end up with a custom gas block to get the adjustment style I want. But, the venting and history of the tubes is well received, I'll look into that.

Turning a new piston is not beyond me, but it wouldn't be heat treated then. I was hoping to stick with mostly stock parts where ever I can. Since the pressure is higher closer to the chamber, I'm going to use a krink piston if possible. I was planning on optics so a front or rear sight doesn't matter to much to me.

I don't think I'm going to have an issue with cycling subsonics. I found a guy that got 180s to cycle with a slow powder and no changes to the gas block. I think my subsonic bullets should be fine, but I would like to retain the ability to shoot supersonic, which means custom gas block work.

I am currently deciding on the gas system. I found two ways to make the AK adjustable. One, like you said, add a restrictive screw. The other is to allow a portion of gas to vent as soon as it enters the gas block. The new RFB carbine uses this method I think. I'm still wrapping my head around if that has any advantages in sound or efficiency. I guess it will depend on how much range I need for sub and super loads.

I'll make pictures and see. It always helps to sketch things out.

Other than the threads, is there something about the AK...

Other than the threads, is there something about the AK...

Re: Other than the threads, is there something about the AK.

Re: Other than the threads, is there something about the AK.