Patriotism means to stand by the country. It does not mean to stand by the President... - Theodore Roosevelt, Lincoln and Free Speech, Metropolitan Magazine, Volume 47, Number 6, May 1918.
Every Communist must grasp the truth. Political power grows out of the barrel of a gun. Our principle is that the Party commands the gun, and the gun must never be allowed to command the Party Mao Zedong, 6 November, 1938 - speech to the Communist Patry of China's sixth Central Committee
You REALLY should perform a function test before firing a new AR and after cleaning/maintenance. Always STOP if a step fails.
1. Remove all ammunition from the room, triple check rifle to ensure it is not loaded.
2. Cycle action (verifying empty chamber again) and place rifle on safe.
3. Point rifle at a safe backstop and attempt to pull trigger - hammer should NOT fall.
4. Move selector to fire, pull trigger, and hold to rear - hammer should fall.
5. Continue to hold trigger, pull charging handle fully to the rear and release to re-cock rifle.
6. Release trigger - you should hear and feel a distinct click as the trigger resets.
7. Pull trigger - hammer should fall with a distinct click.
8. Pull charging handle to rear and release, then place selector on safe.
I normally repeat steps 2-8 two additional times.
If there is NO click on step 6 or step 7 - push out rear takedown pin and "shotgun" the rifle. Note if the hammer is forward (uncocked) or to the rear (cocked).
If step 6 fails and the hammer is forward - the disconnector is not catching the hammer when the action is cycled.
If step 7 fails and the hammer is forward, the trigger's sear is not catching the hammer.
If step 6 fails and the hammer is cocked, the disconnector is not releasing the hammer.
In your shoes, I would replace the FCG with a known good set and perform a function check. If it fails, the lower is suspect. If it passes, I would correctly install the old set and re-test. If it still fails the function check - dispose of the FCG and replace it. FCGs are cheap - I don't swap individual pieces attempting to fix them.
BTW - it's not easy for an AR to fail in a manner that produces a full auto rifle.
Andy
Last edited by AndyLate; 08-21-20 at 19:58.
Make sure the disconnector spring is installed. This is most likely an issue with the disconnector. As another member stated, it’s allowing the hammer to follow the bolt. If everything checks out with the fire control group, it could possibly be the spacing of the hammer/trigger retaining pin holes, which wouldn’t surprise me. I don’t think I’ve ever heard anything good about TN Arms. I’m surprised they’re still in business.
The disconnect or spring was bad (crushed). I missed this when I was assisting in putting it together. Talk about amateur hour. I did inspect the rest of the FCG and there is nothing out of order, damaged, or out of spec when compared to other parts. I have a replacement and will be trying it out again at my next trip to the range.
Your lower receiver hammer and trigger pin holes could also be off. It doesn't take much wear to take out a lower from pin wear or mislocated holes.
Tennessee Arms lower reassembled with all new parts kit. New brace on the way as well. The lower function checks okay: hammer locks back; safety engages; so on. After I have the brace installed and can function check it with an upper I will get it to the range and report further. Thanks for the assistance.
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