Ambi Safety problem

[badicedog]

HELP... HELP...HELP....
Calling out anyone that can help me figure this problem out. I am in the process of completing a 80% build. I installed the Fire Control parts, the trigger and hammer work flawlessly but I cannot engage the safety. It only rotates about 10 degrees out of the 90 degrees it should rotate into SAFE. When I remove the hammer then it functions properly until I install the hammer again. I'm stumped... This is NOT my first build but the first time I have encountered this...


This is how far the safety will rotate.


Any suggestions/help is greatly appreciated.

[G-forceJunkie]

Perhaps the floor of the FCP pocket is not deep enough, so the rear of the trigger is not allowed to rotate down enough to clear the safety.

[badicedog]

Perhaps the floor of the FCP pocket is not deep enough, so the rear of the trigger is not allowed to rotate down enough to clear the safety.

I thought about this but I'm certain it is. I'm trying to brainstorm other causes and possible fix. Thanks.

[morthrane]

What brand safety? Did you unwittingly pick up a short throw lever? (battle arms makes a 45 degree one, and I think Noveske has a 60 degree lever)

If I'm not mistaken, the receiver has to be cut specifically to accomodate a short throw safety lever.

[badicedog]

It's a factory HK 416 semi Ambi safety.

[chayden]

How does the HK safety measure up to a standard AR-15?
Also, was the trigger an HK 416 variant also? It appears a disconnector for the two triggers are different which may be your binding issue.

HK416 Disconnector


typical AR LPK Disconnector

[xfer42]

It sounds like either the safety hole is a too low, or the trigger is a tad too high. May have to file down the back of the trigger where it hits the safety.

[badicedog]

How does the HK safety measure up to a standard AR-15?
Also, was the trigger an HK 416 variant also? It appears a disconnector for the two triggers are different which may be your binding issue.

HK416 Disconnector
[ATTACH]323236[/ATTACH]

typical AR LPK Disconnector
[ATTACH]323237[/ATTACH]

trigger and hammer are Geiselle SSA

[badicedog]

It sounds like either the safety hole is a too low, or the trigger is a tad too high. May have to file down the back of the trigger where it hits the safety.

Thanks for the suggestion. I'm going to re-measure the cut from the deck to bottom of fire control pocket again. I hope this is not the case.

[peterabbits]

Check the placement of the trigger slot too - might have to open up the front just a tiny bit - this issue prevents the trigger ears from dropping down as well.

[badicedog]

Check the placement of the trigger slot too - might have to open up the front just a tiny bit - this issue prevents the trigger ears from dropping down as well.

Could you elaborate on this a bit more? I'm litterally pulling hairs now!

[xfer42]

If the trigger is held slightly back, it would cause that problem. Make sure it moves forward in the trigger slot (where it protrudes through the bottom of the receiver).

This spot (this is one of my 0% builds. Made the BB too):

[peterabbits]

Xfer42 got what I was talking about. My first couple lowers had the entire pocket and slot and everything just a smidge too far back. I fixed the first one by modifying the trigger but I couldn't fix the second one safely that way. Took me forever and three triggers to figure out what the real problem was. I did get real nice short crisp trigger pulls out of them all way though - using a stock LPK too.


Edit: looking at your first picture again, I think this is your problem - the buffer retaining pin hole looks awfully close to the pocket for the break down pin. If done all at once on a CNC that could mean your trigger slot is also too far back. It's a very small difference.

Could you elaborate on this a bit more? I'm litterally pulling hairs now!

[badicedog]

Thanks a million guys. I'm going to check tomorrow.

[ar15barrels]

Bring it over with your fire control parts.
There are several causes and multiple fixes...