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SBOldMan
05-30-2008, 7:52 PM
Finalizing a build...few issues-

First issue is shown in image 1 with the yellow arrow. The width here is just a few pig hairs narrow and is causing my bolt carrier to stick right there. When I pull the bolt carrier back, it just stays back there and doesn't spring forward unless I smack it or jolt it etc...
Best bet for me to (a)file it (b)pound on it (c)bend/spread it (d)specify other.

Second is more of a learning question. Image 1 shows with the red arrow the sear pulled back in a "ready" position. Now if I manually push the sear down further and pull the trigger, Image 2 with green arrow shows how the single trigger hook grabs the sear and prevents it from firing unless you release the trigger and then pull again. Can someone explain what this function is for, is this the way it is supposed to be working?
http://www.knappfamily.com/trigger.jpg


http://www.knappfamily.com/triggerpulled.jpg

Lateralus
05-30-2008, 9:52 PM
1: Welcome to the wonderful world of AKs. Unlike the sophisticated AR. the AKs parts dont always get along together. Id recommend light filing. Either that or rack the action about 300 times.

2: That is the disconnector. When you pull the trigger, the bolt carrier comes back faster then you can release the trigger. That piece holds the hammer back as the carrier comes forward. If it wasnt there, the hammer would follow the carrier resulting in a 3 round burst. Disconnector problems are the #1 culprit of people going to jail for machine guns.

scotthmt
05-30-2008, 9:58 PM
2: That is the disconnector. When you pull the trigger, the bolt carrier comes back faster then you can release the trigger. That piece holds the hammer back as the carrier comes forward. If it wasnt there, the hammer would follow the carrier resulting in a 3 round burst. Disconnector problems are the #1 culprit of people going to jail for machine guns.

Or it would follow and do nothing

rix
05-30-2008, 10:07 PM
.1 Double check and make sure the bolt carrier in not hanging up on the hammer(like most AK builds)before you start filing on the rails.2 sounds normal to me.

Lateralus
05-30-2008, 10:09 PM
.1 Double check and make sure the bolt carrier in not hanging up on the hammer(like most AK builds)before you start filing on the rails.2 sounds normal to me.

This could be it too. The OP made it sound like it was getting stuck. Ive never had it ride on the hammer hard enough that the recoil spring couldnt return it.

Or it would follow and do nothing

Thats a possibility too. I am NOT going to be the one to find out though. Not after our friend on ARFcom.....

jumbopanda
05-31-2008, 12:40 AM
Your disconnector is working fine. File the rails where the bolt carrier gets stuck.

JeffM
05-31-2008, 1:47 AM
Sounds fine. I wouldn't file anything. Every AK I've ever handled could be made to have the bolt carrier lock back due to interference from the hammer pushing up on the bolt carrier. Just cycle it by hand a bunch of times. Just make sure you don't ride the bolt carrier, meaning slam it back and let it fly forward under full spring power.

Preform the function check below with the top-cover off to see how the trigger/sear, hammer, and disconnecter work together.

Make sure you do a full function check with it unloaded first. You don't want to have bolt-follow issues with live rounds.

Check that it's unloaded, pull the bolt all the way back and let it slam forward under it's own spring power. Pull the trigger. While still holding the trigger back pull the bolt back again and let slam home. Release the trigger then pull it again. You are testing that the hammer is being engaged by the sear. If you get a click the second trigger pull you're good to go. If not the hammer is following the bolt as it goes into battery. If you have hammer following issues it could be the angles of the trigger group, but the double-hook that you have should minimize the chances of that. NDS has a tutorial on their site if you need to work that out.

Builder
05-31-2008, 11:27 AM
The OP made it sound like it was getting stuck. Ive never had it ride on the hammer hard enough that the recoil spring couldnt return it.If one pulls the bolt carrier back slowly enough to get the hammer to hold the bolt carrier, it functions similar to a BHO device for mag changes. Then a quick rack and it chambers a round. Sometimes a quick whack to the side of the receiver will drop the carrier home.
The OP should check the bolt carrier movement (binding) without the FCG installed. Sometimes too much clearance in the top receiver rails will cause the bolt carrier to ride high from pressure of the hammer and get stuck. Just to be complete, check for binding in the gas tube.
Spreading the receiver can bind the top cover and should be done when the receiver is actually bent inward. If it truely is the top receiver rails being too narrow and binding the bolt carrier, then filing carefully can solve the problem. As another poster wrote, use can sometimes solve the problem. Proper use of lube can be helpful. Check for smooth rails without burrs under the edge.
Thanks,
Builder