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Posted: 10/17/2016 6:40:31 PM EDT
Just built an AR using pretty cheap parts.  Fires great.  But fires great when I release the trigger!

I know you can spend a lot of money for this privilege and that ATF is OK with this, however, I have no clue how this is happening.

Looking online seems the consensus is the disco.  BUT, if this disco does what an expensive echo trigger does is this something that should be copied?

Would enjoy your thoughts.

Ken
Link Posted: 10/17/2016 6:45:17 PM EDT
[#1]
Is the disconnector spring in right?



Large end at the bottom.
Link Posted: 10/17/2016 6:57:42 PM EDT
[#2]

Disco or disco spring.


or your crappy parts are out of spec.


Link Posted: 10/17/2016 7:38:49 PM EDT
[#3]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Disco or disco spring.


or your crappy parts are out of spec.


View Quote


This.
Link Posted: 10/17/2016 8:17:56 PM EDT
[#4]
Discussion ForumsJump to Quoted PostQuote History
Quoted:


This.
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:
Disco or disco spring.


or your crappy parts are out of spec.




This.

mostly the second part, I'll wager.
Link Posted: 10/18/2016 5:15:13 AM EDT
[#5]
I believe the disco is out of spec, too. My point is that instead of paying up to $400 for a new trigger system that fires both on the pull and the release of a trigger a very simple and free disco mod achieves the same thing. So maybe I should not. Call this disco I have with the spring inserted correctly crappy?
Link Posted: 10/18/2016 7:08:46 AM EDT
[#6]
I had the same problem on a build.

Filed a little (very little) off the front leg (not catch) of the disconnect. Problem fixed.


Testing was like this:
Dry fire, but hold trigger all the way back.
Rack the bolt to reset hammer.

With bolt seated (closed) properly, SLOWLY release trigger.

IF hammer falls, remove more material

OBVIOUSLY you do this test with an unloaded arm.
Link Posted: 10/18/2016 7:58:35 AM EDT
[#7]
Franklin says the ATF told them if they built a trigger like yours the ATF would consider it a machinegun.



Franklin and Fostech both use designs tha prevent a dead spot in the trigger pull that would allow the hammer to automatically follow the carrier.
Link Posted: 10/18/2016 9:43:34 AM EDT
[#8]
Fostech and Franklin Armory have been approved by the ATF for meeting the definition of “semi-automatic” despite having two shots per “pull” (at least in the conventional sense) of the trigger. To meet the ATF’s requirement, specific movement is required to release both shots and the cycle can be broken by switching the trigger packs back to semi-auto.

Crazy to think that a cheap disco could actually be a viable alternative to these highly engineered triggers!

Maybe I should submit this new "design" to the ATF!

Thanks for the replies.

Ken
Link Posted: 10/18/2016 9:55:12 AM EDT
[#9]


Discussion ForumsJump to Quoted PostQuote History
Quoted:



Fostech and Franklin Armory have been approved by the ATF for meeting the definition of "semi-automatic” despite having two shots per "pull” (at least in the conventional sense) of the trigger. To meet the ATF’s requirement, specific movement is required to release both shots and the cycle can be broken by switching the trigger packs back to semi-auto.





Crazy to think that a cheap disco could actually be a viable alternative to these highly engineered triggers!





Maybe I should submit this new "design" to the ATF!





Thanks for the replies.





Ken
View Quote
Your misunderstanding why ATF is approving their designs. The ability to switch to safe isn't required. If at any point in the trigger pull, the trigger could be held at that single position and the hammer would follow the carrier down after the first shot fires, ATF will consider it a MG.


 
Link Posted: 10/18/2016 1:39:01 PM EDT
[#10]
Link Posted: 10/18/2016 6:55:48 PM EDT
[#11]
Thanks Greg.  Will try this!

Ken
Link Posted: 10/24/2016 10:23:41 AM EDT
[#12]
Discussion ForumsJump to Quoted PostQuote History
Quoted:... Here is a function test that we teach in armorer courses:

1.  Cock the Hammer and put the Safety into the "Safe" position.  Try pressing the trigger, nothing should happen, as this tells you the Safety is working correctly.

2.  Put the Safety into the "Semi" position.  Try pressing trigger, and the Hammer should release from the Trigger and Fire.  Now let go of the Trigger, and manually cycle the Charging Handle rearward, which should now recock the Hammer rearward so it engages the Trigger (Hammer to Trigger Sear Engagement).  Try pressing the Trigger again, and the Hammer should release like before and fire.  Repeat 3-4 times to ensure.

3.  Pull the Charging Handle rearward to manually cycle the action so the Hammer cocks and is caught by the Trigger (Hammer to Trigger Sear Engagement).  Press the Trigger so the Hammer releases and fires.  Now press the Trigger rearward and hold it to the rear while you manually cycle the action by pulling the Charging Handle, which should recock the Hammer so it should be captured by the Disconnector.  Slowly release the Trigger, and you should feel & hear a soft clunk type sound, which is the Hammer releasing from the Disconnector, and the Hammer should now have gone forward and be caught by the Trigger (Resulting in Hammer to Trigger Sear Engagement), then press the Trigger again so that Hammer goes forward and fires.  Repeat 3-4 times.


CY6
Greg Sullivan "Sully"
SLR15 Rifles
TheDefensiveEdge.com
(763) 712-0123

View Quote


HEY, That is what I tried to say.

So, if the hammer does not engage the sear but falls on the firing pin, (firing the rifle), what is the proper fix?

I found that if I caused the disconnect to 'hang on' to the hammer a little longer, it would then engage the sear every time.

Was I wrong in my fix?
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