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 Carbine hammer fails to remain cocked after firing
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makarov9b
Starting Member


USA
12 Posts

Posted - 03/23/2018 :  8:41:25 PM  Show Profile  Send makarov9b an AOL message Send makarov9b a Private Message  Reply with Quote
my carbine problem is that hammer seems to be following bolt as it closes after firing. I then have to manually cock rifle and after firing it happens again and again.. Bolt is fully locked(not a failure to go into battery).. this happens with various ammo. The recoil spring is perfect 10 5/8" long, exactly as when I bought it.(Auto Ordnance carbine). Gas piston has free travel and fully staked in nut. When dry firing it the hammer always stays cocked when I manually cock it. It only happens after firing 1 round.
Please Help!.. I believe it may be a problem with sear or hammer notchhes.. I only had the gun for about 4 months now, and always clean and lube after every firing. I put about 1500 rds. thru it already.

ROBERT GORDON

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Jackp
Veteran Member



USA
1047 Posts

Posted - 03/23/2018 :  10:48:30 PM  Show Profile Send Jackp a Private Message  Reply with Quote
Welcome to the forum from New Mexico!

Does it still manually cock okay if you hold the trigger back while pulling the slide back and releasing? The difference between manually cocking and actually shooting it is that you are pulling the trigger when you shoot it. Possible problem with the sear and/or sear spring. Recoil spring and gas piston are probably okay. If the slide retracts enough to eject an empty cartridge the hammer should already be cocked.

JackP

Edited by - Jackp on 03/23/2018 10:49:16 PM
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makarov9b
Starting Member



USA
12 Posts

Posted - 03/23/2018 :  11:54:16 PM  Show Profile  Send makarov9b an AOL message Send makarov9b a Private Message  Reply with Quote
I'll try that...so if it stays backed(cocked) when I keep trigger depressed- then what does that mean? It's ok? Is it supposed to stay back when I keep trigger pressed? I can't understand the difference between manually operating slide and actual firing with trigger pressed; except for the fact that manual operation is slower than actual trigger firing; and that should not make a difference in operation.
So when I dissasemble firing mechanism and take out sear= what should I be looking for? A worn out edge on contact point with hammer notch?
Perhaps hammer notch is worn out too?

ROBERT GORDON
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Jackp
Veteran Member



USA
1047 Posts

Posted - 03/24/2018 :  10:43:42 AM  Show Profile Send Jackp a Private Message  Reply with Quote
There is a difference in operation.

The sear is there to lock the hammer back in the millisecond the gun fires and the slide is forced rearward. The sear is spring loaded and operates instantly. You cannot release the trigger fast enough to do what the sear does. So, when the slide is cycling normally, when you shoot the rifle, the trigger is ALWAYS in the rearward position (pulled). It's only after the gun is fired and the hammer is already recocked and the target is hit, that you actually get around to releasing the trigger. When you do, the sear resets keeping the hammer cocked.

Now, when you rack the slide manually, are you also pulling the trigger? Probably not, but the hammer locks back anyway because the spring loaded sear will still be pushed into engagement with the notch in the hammer. If you rack the slide while pulling the trigger you are simulating what happens when you actually fire the rifle. The hammer should still lock back. If the hammer does not lock back, the rifle is not operating normally.

Yes, I would suspect a broken sear, a damaged sear spring or possibly some kind of contamination obstructing the sear. I bet the sear contact point and hammer notch is okay. If they were worn, you probably wouldn't be able to cock the hammer manually.

Right now your rifle is unsafe and could fire unexpectedly. A damaged sear could turn it into a machine gun. While troubleshooting this problem, DO NOT USE LIVE AMMO. When you think it's fixed, and you are ready to test it, do not use a fully loaded magazine in case it is a machine gun. Start with two rounds in the mag.

Here is a link to a web site that shows the operation of the trigger/sear/hammer. The animation at the bottom of the page (Trigger Group) shows the correct operation during firing. The animation at the top of the page (Overall Right Side) shows what happens when manually racking the slide. Notice the difference?

You must be logged in to see this link.

If you are still not sure of what to do, see a gunsmith that knows carbines.

Good luck!

JackP
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BEYU
Advanced Member



USA
298 Posts

Posted - 03/24/2018 :  4:11:05 PM  Show Profile Send BEYU a Private Message  Reply with Quote
quote:
Originally posted by makarov9b

The recoil spring is perfect 10 5/8" long, exactly as when I bought it.(Auto Ordnance carbine).



Forgive my silly question. You say you have only had this rifle for 4 months?

It must still be under warranty?

If so, I'd be on the phone to them in an instant...

BEYU

"Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety."

- Benj. Franklin

Edited by - BEYU on 03/24/2018 4:13:46 PM
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makarov9b
Starting Member



USA
12 Posts

Posted - 03/24/2018 :  4:50:57 PM  Show Profile  Send makarov9b an AOL message Send makarov9b a Private Message  Reply with Quote
Jack,
thanks Jack,
I now understand. I just dissasembled the trigger housing with sear, hammer and trigger out. All looks perfectly smooth, no wear nor burrs, etc. Tell me- should I lube all parts before reassembly, or should they be dry(so as not to attract gunk?
And I'm really stumped as to what went wrong in the first place?....

ROBERT GORDON
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makarov9b
Starting Member



USA
12 Posts

Posted - 03/24/2018 :  4:58:07 PM  Show Profile  Send makarov9b an AOL message Send makarov9b a Private Message  Reply with Quote
Jack,
I just noticed that the pin hole in the sear is clearly oval in shape, not round like pin...could that be causing the problem?.. also in the oval hole is a slight projection(not totally smooth)..?
'Is this normal?
Obviously this was all present during the many months I've been firing over 1500 rds, without any problems... so what the heck is going on with this rifle?..

ROBERT GORDON
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Jackp
Veteran Member



USA
1047 Posts

Posted - 03/24/2018 :  5:15:12 PM  Show Profile Send Jackp a Private Message  Reply with Quote
Did it cock when you held the trigger back? If not, I strongly suspect the sear spring. Was it dislodged and binding? Was there gunk around it? Although some would say use grease on the sliding parts, I would just use just a light machine oil on the surface of the hammer notch and on the trigger/sear pin and make sure everything moves freely before installing the big hammer spring. Now that you understand the operation you can observe how the parts interact before attaching the trigger housing to the receiver. Does it match the animation?

BEYU makes a good point. AO doesn't have a great reputation for quality. Many of their parts are investment cast and may have rough spots or maybe short shot (incompletely filled). They may also be insufficiently hardened. Read about it here (The Trigger Housing Group):

You must be logged in to see this link.

JackP
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Tuna
Moderator



3254 Posts

Posted - 03/24/2018 :  7:09:11 PM  Show Profile Send Tuna a Private Message  Reply with Quote
AO carbines are not known for there dependability. If this is only four months old then contact AO about having it fixed by them. Just be ready for a song and dance by them. Their quality control and repair service is hit or miss. Good luck to you.
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Jackp
Veteran Member



USA
1047 Posts

Posted - 03/24/2018 :  7:29:35 PM  Show Profile Send Jackp a Private Message  Reply with Quote
Robert, if you do send in in for repair, let us know what they find. It will help us better understand how to troubleshoot the next one that comes along.

JackP
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BEYU
Advanced Member



USA
298 Posts

Posted - 03/25/2018 :  1:01:02 PM  Show Profile Send BEYU a Private Message  Reply with Quote
Perhaps the best solution is to ask Auto Ordnance to just replace the entire trigger group rather than try to repair individual parts.

I would say it is good policy to give them the chance to do all they can to fix your problem.

And...you could void the warranty by trying to fix the defect yourself or by having a gunsmith attempt it...

After Auto Ordnance has had ample opportunity to make it right, you may still have smaller issues to deal with on your own.

BEYU

"Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety."

- Benj. Franklin
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Jackp
Veteran Member



USA
1047 Posts

Posted - 03/25/2018 :  4:01:23 PM  Show Profile Send Jackp a Private Message  Reply with Quote
Sorry I missed your earlier question. The oval hole is normal. The slight projection on the bottom of the hole is sometimes present but it shouldn't be enough to cause binding. The sear is supposed to move forward and rearward as well as pivoting on the trigger pin. Any chance you can post a picture of that part?

JackP

Edited by - Jackp on 03/25/2018 4:25:55 PM
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Jackp
Veteran Member



USA
1047 Posts

Posted - 03/25/2018 :  4:07:26 PM  Show Profile Send Jackp a Private Message  Reply with Quote
Here's a picture I found of a sear with the slight projection visible. Is yours like this?


JackP

Edited by - Jackp on 03/25/2018 4:24:21 PM
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makarov9b
Starting Member



USA
12 Posts

Posted - 03/30/2018 :  4:23:55 PM  Show Profile  Send makarov9b an AOL message Send makarov9b a Private Message  Reply with Quote
yes

ROBERT GORDON
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makarov9b
Starting Member



USA
12 Posts

Posted - 03/30/2018 :  4:45:30 PM  Show Profile  Send makarov9b an AOL message Send makarov9b a Private Message  Reply with Quote
damn!!! now I fininshed taking apart trigger group(a dog of a job!),, and performed the trigger test(firing and holding back trigger to see if it sets), and all seemed fine.
Just went to the range and fired 20 rounds,... the first 3 or 4 rounds fired normal- then the "fun" began-- it started firing full automatic!!. it did this till the last 2 rds. in mag; which then started the old problem of the hammer not setting back to fire position, and I had to recock and fire single shots for the last 2 rds.
then i loaded another 10 rds in mag and the same thing happened again,
a few shots semi-auto, then 3 and 4 rds, bursts fully auto!!
What's going on? I suspect a weak trigger spring? or the sear>?
but the sear seemed fine to me(no wears or any other suspect marks)... any clues please???

ROBERT GORDON
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makarov9b
Starting Member



USA
12 Posts

Posted - 03/30/2018 :  4:55:05 PM  Show Profile  Send makarov9b an AOL message Send makarov9b a Private Message  Reply with Quote
also another problem is that when I called Auto Ord. and asked them for their turn-around time- they said 9 weeks!!
and I am in process of relocating to Florida from Texas within 2 months- so I can't send it back to these monkeys until then.. bummer! also the guy in their repair dept. who I keep getting to speak to is very abrupt and only keeps saying- just send it back to them; and refusing to tell me possible causes of problems as I mentioned. I could then just order the offending parts and install myself(it's not rocket science.. since I already took it apart and re-assembled no problem).

ROBERT GORDON
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Tuna
Moderator



3254 Posts

Posted - 03/31/2018 :  10:39:51 AM  Show Profile Send Tuna a Private Message  Reply with Quote
Robert, Best not to be telling them you took it completely apart and now it will fire a few rounds full auto as they can say you caused it to happen and voided the warrantee. When you get settled in Florida then send it back to them including a written note or letter describing what is happening and let them take it from there.
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makarov9b
Starting Member



USA
12 Posts

Posted - 03/31/2018 :  1:03:15 PM  Show Profile  Send makarov9b an AOL message Send makarov9b a Private Message  Reply with Quote
I agree. But I would really like to take care of this myself if someone could tell me what is wrong?

ROBERT GORDON
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Jackp
Veteran Member



USA
1047 Posts

Posted - 03/31/2018 :  1:51:54 PM  Show Profile Send Jackp a Private Message  Reply with Quote
Why do you suspect a weak trigger spring? Is the trigger spring properly engaged with the trigger? You say disassembly was a "dog of a job". What in particular did you have difficulty with? I find installing the trigger spring without the proper tool is difficult. Also, compressing the hammer spring is hard to do as well. It's easy to see if the hammer spring is installed properly, not so much with the trigger spring. Sometimes it slips down behind the trigger but looks like it's installed correctly. It may push up against the back of the trigger making it seem to be working....sorta. That might be why it works okay manually but when you shoot it, it doesn't. Lots of shock and vibration while shooting that you don't see when operating it manually. I guess without actually seeing your carbine, there's not much more I can suggest.

JackP

Edited by - Jackp on 03/31/2018 3:34:19 PM
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Jackp
Veteran Member



USA
1047 Posts

Posted - 03/31/2018 :  8:53:51 PM  Show Profile Send Jackp a Private Message  Reply with Quote
BTW, I suggest you don't test your carbine with a fully loaded magazine. One round at a time. You don't want it to go full auto again.

JackP
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makarov9b
Starting Member



USA
12 Posts

Posted - 04/01/2018 :  4:20:56 PM  Show Profile  Send makarov9b an AOL message Send makarov9b a Private Message  Reply with Quote
quote:
Originally posted by Jackp

Why do you suspect a weak trigger spring? Is the trigger spring properly engaged with the trigger? You say disassembly was a "dog of a job". What in particular did you have difficulty with? I find installing the trigger spring without the proper tool is difficult. Also, compressing the hammer spring is hard to do as well. It's easy to see if the hammer spring is installed properly, not so much with the trigger spring. Sometimes it slips down behind the trigger but looks like it's installed correctly. It may push up against the back of the trigger making it seem to be working....sorta. That might be why it works okay manually but when you shoot it, it doesn't. Lots of shock and vibration while shooting that you don't see when operating it manually. I guess without actually seeing your carbine, there's not much more I can suggest.


When I removed spring it was sort of distorted in shape. It was bent somewhat to one side and one of the "legs" was bent inwards(not the same length as the other one). This may be causing the problems.
I am going to order from OA a new trigger spring, along with a new sear, pin, sear spring & hammer- just to be sure. When I reassemble and it still has problems; it will be going back to OA then.
Sounds like a plan?

ROBERT GORDON
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Jackp
Veteran Member



USA
1047 Posts

Posted - 04/01/2018 :  7:00:10 PM  Show Profile Send Jackp a Private Message  Reply with Quote
It might be a good idea to get a trigger spring insertion tool to make it easier to install the new spring.

You must be logged in to see this link.

Be sure to let us know how it turns out. Good luck!

JackP
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Tuna
Moderator



3254 Posts

Posted - 04/01/2018 :  7:56:04 PM  Show Profile Send Tuna a Private Message  Reply with Quote
Good plan? NO it's not. I would strongly suggest that you send it back to AO other wise you can very well void any warrantee on it. That is something they would be happy to say to you considering your ordering parts from them. If your set on doing it yourself then you can use a strong piece of fishing line to set the trigger spring in place. Might need a small screw driver to set the legs properly. Quick, cheap and easy to do.
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makarov9b
Starting Member



USA
12 Posts

Posted - 04/03/2018 :  10:01:42 AM  Show Profile  Send makarov9b an AOL message Send makarov9b a Private Message  Reply with Quote
quote:
Originally posted by Tuna

Good plan? NO it's not. I would strongly suggest that you send it back to AO other wise you can very well void any warrantee on it. That is something they would be happy to say to you considering your ordering parts from them. If your set on doing it yourself then you can use a strong piece of fishing line to set the trigger spring in place. Might need a small screw driver to set the legs properly. Quick, cheap and easy to do.


I still feel I should try myself, considering how poor their repair dept. is said to be. I see there is a trigger spring tool on Amazon for $5.. are you familiar with how that tool works? It looks like a right angle piece with one open side..

ROBERT GORDON
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Jackp
Veteran Member



USA
1047 Posts

Posted - 04/03/2018 :  12:44:33 PM  Show Profile Send Jackp a Private Message  Reply with Quote
Here's how it works:

1). Shove the spring in the open end of the tool.

2). Poke the tool through the hole in the back of the trigger housing with the spring oriented at 90 degrees from its final position.

3). Rotate the tool 90 degrees to engage the spring with the trigger.

4). Remove the tool while keeping the spring engaged with the trigger.

5). Check to make sure the spring is still properly engaged with the trigger.

Takes just a few seconds.

Some will say you can do the same thing with an empty carbine case. This will not work with any of my USGI carbines. The case is a press fit in the trigger spring hole. However, who knows, it might work with your AO. Maybe the hole is larger. Worth a try before spending $5.

JackP
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makarov9b
Starting Member



USA
12 Posts

Posted - 04/03/2018 :  6:38:29 PM  Show Profile  Send makarov9b an AOL message Send makarov9b a Private Message  Reply with Quote
great idea and info ...
I'll be sure to try it and let you all know what gives...

ROBERT GORDON
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