AK 47 in 5.56

[greg vess]

Yes as a matter of fact. Just got the gun today. The gun will cycle manually just fine. The owner says it won't cycle when shot. I inspected the gas piston and there is quite a bit of wear on the front and middle rings. I actually looks like its been filed. Now my first impression was the bolt is not getting thrown back far enough to catch the lip of the round. You should also know it has a suppressor on it and is permanent to meet barrel length requirements. I would think that would add gas pressure. Everything looks in order except for that piston wear. It looks like to me a lot of gas could pass by that piston wear. What are your thoughts.

 

[mikey357]

Yes as a matter of fact. Just got the gun today. The gun will cycle manually just fine. The owner says it won't cycle when shot. I inspected the gas piston and there is quite a bit of wear on the front and middle rings. I actually looks like its been filed. Now my first impression was the bolt is not getting thrown back far enough to catch the lip of the round. You should also know it has a suppressor on it and is permanent to meet barrel length requirements. I would think that would add gas pressure. Everything looks in order except for that piston wear. It looks like to me a lot of gas could pass by that piston wear. What are your thoughts.

Sounds like it probably is the Gas Piston--Luckily, they are not very expensive, and are easy to replace--That is certainly where I would start, given what you found when you got "Into" the Rifle....mikey357

 

[greg vess]

I took the whole gun apart yesterday and the piston has a good tight fit into the site post/gas block. So I believe the problem is elsewhere. I was reading something about a single stack bolt and a double stack bolt. Have you had any dealings with these.

 

[Wolf six]

Ak arent Ar's you might want to send this to jj or ott

Check the ID of the gas chamber then check the OD of the gas piston. use micrometers
Does it have a tapco trigger in it?
What kind of ammo was the customer using?
what is the diameter of the gas port on the barrel?
Does it have a recoil buffer?

Reading the things you are posting makes me think you arent qualified to work on the guns people are bringing you

 

[wwboater]

Reading the things you are posting makes me think you arent qualified to work on the guns people are bringing you

Ouch, harsh but so true. Messing with things that can explode in peoples faces and hands should be left to the folks that have the skills and knowledge to do so..... and insurance for accidents.

 

[greg vess]

These guns are simple machines. Even though they are different the concepts hold true. I use to be a mechanic specializing in electronics, hydraulics, phnuematics, diesels, and two and four stroke engines. I also build and tune new computer controlled 700 HP engines in my spare time. Just because some people are scared to delve into the unknown it does not intimidate me. I can build, fix and work on anything mechanical. I am not claiming to know everything because I do reach out and gain knowledge when and where ever possible. This problem is a simple fix It sometimes takes a little time to figure out. Yesterday I had the gun fully apart in 5 minutes and never even held one and now I have a complete working knowledge of the gun. My initial diagnosis is the the bolt carrier is not being thrown back far enough to catch the rim of the cartridge. I will have to wait and go to the range to verify that. I was just reading and making sure all the parts that were in there were correct. I have been working on guns for over 30 years so another gun doesn't scare me away. Most people look at something foreign and run away while pulling their thongs out of the crack of their ass. NOT ME!!!! Enough said.

 

[mikey357]

As Wolf Six suggests, if it has a Recoil Buffer THAT could be a problem...Also, is the Gas Tube VENTED, or Solid? Some have a series of Vent Holes drilled in 'em from the Factory, some do not--IF the gun originally had a NON-Vented Gas Tube & it was replaced with a Vented unit at some point, THAT could cause malfunctions, too...HTH....mikey357

 

[greg vess]

I didn't mean to sound all arrogant but no mechanic in the world can remember every torque spec and bearing tolerance of every engine he works on. Manuals are the key to a excellent technician. Same goes for the guns. Knowledge is key when working with anything mechanical and I don't have a manual. Before I buy one I will reach out and see if this problem has been encountered before for a short cut. I have all the necessary to tools to check tolerances make modification if I need to. I am going to take it apart again tonight and check those things. Last night I just checked how the piston fit into the gas block because the piston had unusual wear on it. I will go in and give it a very close look later.

 

[bambam]

What is the make and model? Pics?

 

[laserbeam1k]

Could be the ammo try brass instead of steel