Possible fix for Hiperfire Eclispe Doubling/Bursting. Suggestions needed.

[theix]

I have a Angstadt Arms UDP-9 with a heavy, long and gritty mil-spec trigger which was immediately replaced with a Hiperfire Eclipse. I can always induce doubling/bursting whenever I try to shoot fast by not pulling the trigger deliberately all the way through. By deliberately pulling the trigger and holding it before letting it off for a reset, it will not cause doubling/bursting. No hammer follow during dry fire.

 

After some research I found out that some safety selectors are not compatible with Hiperfire triggers but mostly due to the cut away for some non-90 degree throw. I had a Geissele 90 Posi-snap Ambi Safety Selector installed which is not in the compatibility issue list.

 

Then I found Hiperswitch that Hiperfire advertised to be compatible with all of their triggers so I gave it a try. 0 doubling/bursting for 150 rounds straight but I don't like the 60 degree throw and grittiness of the throw. I noticed that the trigger reset and trigger over-travel when Hiperswitch installed is very slightly longer than Geissele Posi-Snap. I have yet to measure the depth of the cut away in safety selector barrel of the Hiperswitch but the Posi-snap measures around 5.97mm, the original mil-spec safety selector measures 5.85mm.

 

My theory is that the depth of the cut away in safety selector barrel of the Posi-Snap (that allows the trigger to rotate when pulled) is not deep enough so the engagement of disconnector and hammer hook is less than ideal or no engagement when shooting fast (not pulling the trigger deliberately) but safety selector barrel of Hiperswitch does. This combines with violent BCG movement = doubling/bursting.

I really want to go back to the Posi-Snap as I like the way the throw feels but the bursting is a no-no for me. Is it a good idea to file the cut away of the safety selector barrel to allow for a little more trigger over-travel?

My current setup are
- UDP-9
- JP BCG with SCS (Full-stroke enhanced version)
- Hiperswitch Safety Selector

- Hiperfire Eclipse with Red toggle spring (3.5lbs trigger)

 

I'm relatively new to the PCC/AR world. Any suggestions will be much appreciated.

[mitommy]

I run a Timber Creek 45 degree ambi selector. I have not had a burst fire since making the change. I wanted a less than 90 degree throw and I believe Hiperfire suggested this as an alternative to theirs. I also didn’t like the idea of the selector levers being plolymer (as I believe the Hiperfire is) 

 

it is available on Optics Planet for about $30

Edited November 3, 2022 by mitommy