[SweTiger]

Hi,

I'm hoping for some advice on my recent HK 770 incident before I bring the gun to the gunsmith.

Yesterday I experienced a rather scary malfunction on my HK 770.
The first indication of something being wrong was when the gun got stuck in safe even though I'd chambered a round and the safety was disengaged. It simply wouldn't fire and you could feel the trigger was locked. This happened several times but got remedied by operating the action a few times. The gun fired normally twice in six attempts. In hindsight we should have stopped here and taken the gun apart instead of keep trying.

However, when my friend got behind the gun and pulled the trigger it fired both rounds in the magazine in full auto. Needless to say we called it a day and packed up after this.

How is this possible and what could have caused it?
All feedback is appreciated.


Btw. I actually have slow motion video of the incident. It looks a bit scary since the second round is unexpected.


Best regards,

 

[dbj2003]

Technically you are in possession of a machinegun. You should proceed very carefully.

 

[SweTiger]

I know. I live in Scandinavia we have pretty strict laws for ownership. The plan is to get it fixed by an authorised gunsmith (and if necessary, contact the police). I just want more knowledge before starting that process.

 

[warbirds]

A malfunction is not a machine gun. Is a firearm needing repair.

Sent from my SM-G920T using Tapatalk

 

[wachtelhund]

Hi,

I'm hoping for some advice on my recent HK 770 incident before I bring the gun to the gunsmith.

Yesterday I experienced a rather scary malfunction on my HK 770.
The first indication of something being wrong was when the gun got stuck in safe even though I'd chambered a round and the safety was disengaged. It simply wouldn't fire and you could feel the trigger was locked. This happened several times but got remedied by operating the action a few times. The gun fired normally twice in six attempts. In hindsight we should have stopped here and taken the gun apart instead of keep trying.

However, when my friend got behind the gun and pulled the trigger it fired both rounds in the magazine in full auto. Needless to say we called it a day and packed up after this.

How is this possible and what could have caused it?
All feedback is appreciated.


Btw. I actually have slow motion video of the incident. It looks a bit scary since the second round is unexpected.


Best regards,

SweTiger,

The double fire has to be either the safety, hammer or in the trigger group it self. I would first disassemble the gun and remove the safety. Inspect the safety for damage and the hammer were it contacts the safety. I do most of my own trigger work, but I draw the line on the 630 and 770 trigger groups. If no apparent damage on the safety or hammer then take it to a gunsmith. I suspect the problem is in the trigger group, a pin or spring worked loose. Does your trigger group still have the side plate that hold all the pins in?

 

[RegularGuy461969]

I'd send it straight to an Armorer if for no other reason than how much my 770's trigger group intimidates me.

Please report back on cause and fix once you know.


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[AGG]

Welcome to the site--- let us know what the gunsmith/armorer finds!!! :biggrin:

Tony

 

[SweTiger]

SweTiger,

The double fire has to be either the safety, hammer or in the trigger group it self. I would first disassemble the gun and remove the safety. Inspect the safety for damage and the hammer were it contacts the safety. I do most of my own trigger work, but I draw the line on the 630 and 770 trigger groups. If no apparent damage on the safety or hammer then take it to a gunsmith. I suspect the problem is in the trigger group, a pin or spring worked loose. Does your trigger group still have the side plate that hold all the pins in?

Thanks, the trigger group is my guess too. It's remarkable how flimsy and cheap it seems compared to the rest of the rifle. It's like it was made by Swatch. I'm not sure about the side plate, I bought the rifle second hand and no parts should be missing.
I'll take the trigger group out next and see if I can find something which looks odd or worn down.

Also, I've spoken to a gunsmith and he said it should not be problem legally as long as I did not use the rifle before fixing it.

I'll report back when I know more.

Thanks for your support and opinions, it's highly appreciated.

 

[wachtelhund]

Thanks, the trigger group is my guess too. It's remarkable how flimsy and cheap it seems compared to the rest of the rifle. It's like it was made by Swatch. I'm not sure about the side plate, I bought the rifle second hand and no parts should be missing.
I'll take the trigger group out next and see if I can find something which looks odd or worn down.

.

Actually the trigger group is pretty stout the way it is made and machined very well. A number of the springs are doubled so they can fit inside the trigger group. But you correct when looking at some of the pins they are so small, I'd never be able to get them in with my fingers. The side plates are very thin and are held on with two folded snaps on both ends of the trigger. Their purpose is to keep the various trigger pins from slipping out of the trigger housing side. If a side plate is missing, it is very easy to lose a pin or two.