[scottMO]

Still trying to exercise the demons out of my clones. In my reverse stretch gun, it runs all day single fire with the orig housing and pack. With my sear pack and the same housing, if I insert a full-ish mag and hk slap it, I have a dead trigger. If I leave the mag in and manually kick out the live rd and load a new round, its still dead. Starting over, hk slap, dead trigger, IF I remove the mag and slowly pull the cocking lever back just a little, not ejecting the live round and go forward again , the trigger is now alive(I can feel the pressure on the trigger ). I can now reinsert the mag and dump the still chambered first rd and all the rest in 1 long burst.

On a side note, this gun does have a wide slot for the mag catch and therefore the mag catch and mag do move/wobble a bit. I would think that this could cause loading problems but how could this affect the trip?

 

[The_Crow]

I would check the shelf height. Try shimming the housing just a bit so it fits tighter.

 

[99HMC4]

From the rear of the gun look forward down the side. Does your trigger housing line up with the receiver or is the gap bigger by the mag well than the rear by the stock? Sit on a chair and place the gun upside down on your lap, grap the trigger guard and try to move the housing up and down. Is there any play?

 

[scottMO]

no play in the housing and its level. does the entire pack need to be shimmed upwards? worn trip?

 

[DJF]

scottmo,
more than likely a worn sear trip lever. It doesn't take much. Does it act the same way if you only have let's say...5-10 rounds in the mag? Using HK mags?
Dj

 

[JTinIN]

If one is having issues, clean the gun and then coat the bottom of the bolt carrier and the trip lever with layout dye. Hand cycle and see where and when the trip is contacting.
Next make a shim on the trigger pack and see if you get a different contact point.
ITW Dymon | Dykem® | Layout Fluid

 

[Chopstix Kid]

If I am understanding the symptoms correctly...

You probably have a little bit more carrier play than ideal which was probably done to help prevent binding of the carrier. As such, a full (or nearly full) magazine is applying enough upwards pressure on the bolt to lift the carrier up enough so that the trip lever does not fully press down on the auto-sear to release the hammer. This appears to be evident when you remove the mag (removes upwards pressure), pull back slightly (resets "normal" level of the carrier) and release.

Here's how you can test this...

1) Unload the gun. Move selctor to semi-auto and HK slap. Pull the trigger and see if the hammer drops. If it does not, remove the lower and inspect to see if the auto-sear has released the hammer. I would suspect if this condition exists then the auto-sear will still have the hammer engaged indicating that the pack is sitting a little bit too low on the gun or the trip lever is excessively worn. If the hammer does indeed drop, proceed to test #2.

2) Perform the above test VERY VERY VERY CAREFULLY with the gun loaded, pointing in a safe direction with a FULL mag. If test #1 passes and test #2 fails, assuming everything in the configuration of the firearm is correct, I'm guessing it safe to say that the bolt-group as too much play in the receiver and the mag is pushing it up too high.

 

[kwesi]

Scottmo: I had to raise the height of my Registered Trigger Housing by adding very thin shim in the SEF housing at the shelf end (As suggested by Ghilliebear). Now my SW5 finished upper purrrs f/a. This got the trip lever to the correct height.

 

[Chopstix Kid]

It also occured to me that if your carrier is a re-weld, it could have been machined back just a little to far. This could also cause a very slight amount of carrier play to not to depress the trip lever enough.

 

[scottMO]

Pics of the mag catch:

no mag:

With mag in:

Should the mag catch be level (do I need to shim the mag catch or add material to the mag catch slot to level it up/close the gap), so it doesnt move near as much?