M1 Carbine troubleshooting

Hello, this is my first post on here. I recently acquired an Auto Ordnance M1 repro carbine from an online auction. After winning it (which i was hoping i wouldnt) I have had instant issues since receiving this rifle.

This is also my first carbine so any help would be greatly appreciated.

Upon receiving it I disassembled and cleaned it. I was a little weary at first seeing a stainless round bolt that appeared to be not original to this rifle and had a little slop feeling to it. Again new yo carbines but one thing I noticed is the bolt move forward a bit and rotate right when dry fired.

The first real issue I ran into was the stuck gas piston. Its staked so I wanted to try anything and everything before trying to replace it. I tried ballistol on it and in barrel , i tired CLP , I also tried using an air compressor down the barrel blocking the chamber. Everything has been a no go.

I then decided to try to fire it to see if a round would have enough pressure to free it up. I was using Federal soft point new production ammo. First shot , click. Bolt somewhat stuck closed and had to bang on charging handle to eject. Ery light primer strike, that happened another 3 times.

Bought and installed new hammer spring and operating spring. Still same results. I did put two rounds in after light primer strike and they did fire but again bolt stuck closed.

Whats next ? Any advice before rebuilding bolt with all new parts or new bolt completely?

Thanks for the reply. So I shouldnt put together a new bolt and give it a go? Could the stuck piston be a source of any of the above listed results?

maxxhavoc said:

First off, welcome to THR. Wish I had my AO handy to work through this with you a little. It sounds to me like someone may have swapped the bolt (at least) with another rifle. If so... Don't try to get it to fire again without checking headspace.

Give me a couple days and we can compare some pictures. My AO is every but as reliable as my GI. But I suspect someone had used an AO to replace parts on a GI they want to sell. Can you take some pictures of the bolt?

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Theres a few pictures I had on my phone already. The picture of the rounds was one after the first light primer strike and the second is what it looked like after the second strike which fired. Every time after round fired though bolt would be stuck closed.

HankC said:

The stuck piston likely the cause if connected to bolt, but I don't know enough about M1 Carbine.
Bolt move forward and rotate when dry fire is likely the reason you have light primer strikes. It indicates the bolt was not fully closed and the hammer strike energy is wasted on pushing the bolt close instead of on the firing pin. I had a RPK did that when new and it was a rough spot on the corner of the bolt carrier cam that turn the bolt when close. Polished the rough spot and fixed. It may just wear in if your rifle is new, but check! Also check the bolt lugs, maybe rough or too tight. Find out what is binding that resist bolt closing. Can your hand push the bolt to close? May be the rails need lube or rough. Let it run wet when new.

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I do not believe this is a new rifle, it seems to have wear throughout. When i try to push the bolt forward when its closed it moves up but only a little bit. Its more of a rotation to the right when dry fired than forward. The bolt feels pretty smooth pulling charging handle back and forward. I did grease the rails and everything else had a cleaning with ballistol so has some lubricant on it.


I did just dry fire it and tried pushed bolt forward and back and did not have the little bit of movement like it did before firing, if that means anything.

These pictures show the movement front to back before dry fire.

CapnMac said:

I wouldn't put the money into it that way, when it probably needs a trip back to the factory.
My 2¢

There's a certain amount of play in a working M-1, and about what you describe. It needs a bit of movement to get the lug to rotate, and start the extraction process.

That gas piston being sticky is a major problem, if its geometry is off, that short stroke will "mis-time" and not with good side effects.
Like not having enough energy to kick the bolt back. Or kicking it back random amounts so that rounds are not fully up to the bolt face, giving light primer strikes.

Bad geometry on AO carbines is a known problem with them, and as a major reason for factory returns.

I'm trying to remember if AO uses a casting for this part. Cast parts are away to reduce machining costs. But they are very tricky to set up the machining to get collinear and concentric operations performed.

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Thank you for the info . I already ordered a bolt tool so im gonna take it apart and give it a good cleaning and see if that makes a difference. Then i was gonna start swapping least expensive parts probably starting with the firing pin just to rule that out. On AO site I could have all the parts and pre order on flat bolt for $115 total for everything. Seeing as the owner of the auction company is sending me a $100 check to cover costs trying to make right on it I was gonna try that.

If that fails or I cant get the staked gas nut off then I will see if I can send it in.

bk42261 said:

I'd be afraid that if you started "swapping parts", any kind of warranty you may have would be voided.

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I dont have any warranty on it , I won it at an auction for $450. I was not able to see the gun before or after bidding. I honestly did not think i was going to win it but I guess the people that were at the actual auction could see something the photos and ad didnt show or say.

maxxhavoc said:

It looks like the op rod is hitting the upper handguard. See if removing that helps the bolt go farther into battery.

Remove that and post pics, especially showing the left bolt lug position, also comment on any changes in fore/aft play.

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It doesnt appear that the handguard is hitting it but I will dremel a little off on the top and bend out the side just a bit to make sure there is no contact. The movement in the bolt is the same as it was without handguard on.

carbine85 said:

It looks like someone tried to fix a problem by polishing up some parts and the feed ramp. One of the pictures shows the bolt not going into battery all the way. The Carbine will have light stricks if this happens.

1) Get a headspace gauge and see if the headspace is correct ( too short). It may not have been reamed properly.
If you can't get the gauge, use an unfired case (not a live round) and check the headspace without the recoil spring. The bolt should rotate into place with a small amount of pressure. Measure the case length for maximum length.
2) Remove the gas piston nut with the proper tool and get that freed up.
3) If the bolt just isn't rotating properly I would send it to AO and have them fit a new bolt

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Thank you for more information! Is the bolt getting stuck after shooting the same cartridge twice after a light primer strike a result of one of the above issues or a separate issue on top of the rest?

carbine85 said:

It looks like someone tried to fix a problem by polishing up some parts and the feed ramp. One of the pictures shows the bolt not going into battery all the way. The Carbine will have light stricks if this happens.

1) Get a headspace gauge and see if the headspace is correct ( too short). It may not have been reamed properly.
If you can't get the gauge, use an unfired case (not a live round) and check the headspace without the recoil spring. The bolt should rotate into place with a small amount of pressure. Measure the case length for maximum length.
2) Remove the gas piston nut with the proper tool and get that freed up.
3) If the bolt just isn't rotating properly I would send it to AO and have them fit a new bolt

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I have been trying to find the forster headspace gauges but are out of stock everywhere. I will get some new brass to try that.

I wanted removing the gas piston but and piston to be the last thing I have to do if everything else fails since its staked. I need to pick up the tool. I read about “ironing” it out if staked so just have to go slow i guess.

Also a last ditch effort sending it to AO seeing as labor is $65 an hour and im already getting close to wait a brand new AO rifle would costs with the parts and tools im getting to get this shooting.

carbine85 said:

If your piston is stuck outward not allowing the operating rod to move forward the bolt isn't going to rotate all the way. That can result in a light strick and preventing an out of battery detonation.
You can purchase a piston nut tool from any number of sources.
Does the bolt rotate into battery all the way without a round in the chamber?

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My piston is stuck all the way in making it difficult to try to get anything on it such as the 308 case trick . It seems to go all the way into battery but has some play in it. Although another replier stated it looked like it was not completely in battery in one of my above photos

Ok, so I looked at the couple fired cases I have from the carbine and noticed a ring around the case about a 1/4 up from the extractor groove and a slight bulge on it. So it seems I have an excessive headspace issue. If that is true whats the easiest or cheapest fix? Could a new bolt help or does the barrel need to be fixed or swapped?

Ok, so I looked at the couple fired cases I have from the carbine and noticed a ring around the case about a 1/4 up from the extractor groove and a slight bulge on it.