Ar gas issue...i think.

[Allsmiles]

Another thing to check and rule out. Check the charging handle for being bent. I had a buddy have something like this going on and charging handle was bent enough to bind the BCG. It was bent up enough that it was hard to pull out and wouldn't go back in without force. Seems someone had charged the rifle and pulled up on the handle with a lot of force.

 

[Guthrie]

Another thing to check and rule out. Check the charging handle for being bent. I had a buddy have something like this going on and charging handle was bent enough to bind the BCG. It was bent up enough that it was hard to pull out and wouldn't go back in without force. Seems someone had charged the rifle and pulled up on the handle with a lot of force.

I ran it with the other bolt carrier group and it ran fine.

 

[CQB27]

Do the easy stuff first.

Remove the firing pin retaining pin, firing pin, cam pin and the bolt from the carrier. What you will be left with is a stripped bolt carrier with the gas key installed (the bolt carrier assembly)
Remove the charging handle from the upper
Check the bolt carrier assembly fit by sliding it in the upper until the carrier face (front of the carrier) bottoms out on the barrel extension.
The bolt carrier assembly should move freely inside the upper and the key should slide over the gas tube with very little to no resistance. Major resistance means an out of spec/misaligned carrier key.

If that seems to work fine, reassemble the bolt carrier group (bolt, cam pin, firing pin, firng pin retaining pin installed) install the charging handle back into the upper reciever and put the bolt carrier group back in the upper. With the tail of the bolt carrier assembly still sticking out the back of the upper receiver, push the charging handle forward until it locks. Now use finger pressuer on the tail of the bolt carrier group to push it forward until the bolt cams and locks into the barrel extension. It should only take a slight push to get the bolt to lock. Now pull the charging handle to the rear to cam and unlock the bolt, again only a slight tug should get it done. Any major resistance could mean an out of spec cam pin or bolt lugs.

If that seems to work, take bolt carrier assembly you already know works and install the bolt, cam pin, firing pin and firing retaining pin from the non working bolt carrier group. Fire the rifle and check for malfunctions. No malfunctions the bolt and cam pin are good to go. If it malfunctions you know either the bolt or cam pin is out of spec. If everything works fine, do the same thing with the known working bolt, cam pin, firing pin, firing retaining pin nd the non working bolt carrier assembly. If it malfunctions then the bolt carrier assembly is out of spec. That could mean an out of spec carrier key inner diameter or the surface that mates with the carrier is not true, or the hole machined in the carrier that mates of with the key is out of spec, or the carrier surface that mates with the key is not true.

The bottom line is once you figure out what part is out of spec you may or may not be able to fix it. An out of spec carrier key or cam pin can be replaced. An out of spec carrier assembly/bolt/bolt lugs needs to go in the trash. During the last big gun scare there were companies pumping out AR small parts that were absolute crap. It's possible the new to you bold carrier group might have some of those imbedded in it.

 

[CQB27]

View attachment 3039179

That bolt face has the typical look of a new bolt with one mag run on it. Excessive wear on the side of the lugs would be what you would want to look for. If that is present then it could indicate an out of spec bolt or a clocked receiver extension. I clocked receiver extension is cause by damage to the barrel extension/barrel index pin or upper receiver index pin slot during the barrel install. The fact that everything worked prior to the new bolt carrier group being thrown int the mix means a clocked barrel extension is very unlikely.

 

[Guthrie]

Do the easy stuff first.

Remove the firing pin retaining pin, firing pin, cam pin and the bolt from the carrier. What you will be left with is a stripped bolt carrier with the gas key installed (the bolt carrier assembly)
Remove the charging handle from the upper
Check the bolt carrier assembly fit by sliding it in the upper until the carrier face (front of the carrier) bottoms out on the barrel extension.
The bolt carrier assembly should move freely inside the upper and the key should slide over the gas tube with very little to no resistance. Major resistance means an out of spec/misaligned carrier key.

If that seems to work fine, reassemble the bolt carrier group (bolt, cam pin, firing pin, firng pin retaining pin installed) install the charging handle back into the upper reciever and put the bolt carrier group back in the upper. With the tail of the bolt carrier assembly still sticking out the back of the upper receiver, push the charging handle forward until it locks. Now use finger pressuer on the tail of the bolt carrier group to push it forward until the bolt cams and locks into the barrel extension. It should only take a slight push to get the bolt to lock. Now pull the charging handle to the rear to cam and unlock the bolt, again only a slight tug should get it done. Any major resistance could mean an out of spec cam pin or bolt lugs.

If that seems to work, take bolt carrier assembly you already know works and install the bolt, cam pin, firing pin and firing retaining pin from the non working bolt carrier group. Fire the rifle and check for malfunctions. No malfunctions the bolt and cam pin are good to go. If it malfunctions you know either the bolt or cam pin is out of spec. If everything works fine, do the same thing with the known working bolt, cam pin, firing pin, firing retaining pin nd the non working bolt carrier assembly. If it malfunctions then the bolt carrier assembly is out of spec. That could mean an out of spec carrier key inner diameter or the surface that mates with the carrier is not true, or the hole machined in the carrier that mates of with the key is out of spec, or the carrier surface that mates with the key is not true.

The bottom line is once you figure out what part is out of spec you may or may not be able to fix it. An out of spec carrier key or cam pin can be replaced. An out of spec carrier assembly/bolt/bolt lugs needs to go in the trash. During the last big gun scare there were companies pumping out AR small parts that were absolute crap. It's possible the new to you bold carrier group might have some of those imbedded in it.

Man i really appreciate all of that information. It passed all of those tests. I wish i would've thought to put the parts in my other carrier earlier today. Im gonna talk to one of the other members that offered to check it out and go shoot it after that. Once again, thank you sir.

 

[NWSharpshooter]

I had a Ballistic advantage bolt that came with rings that really dragged in the carrier. It would short stroke almost every shot. I worked the action a couple of hundred times and then shot it a couple of hindered more. The rings wore in and I never had another issue.

 

[Bagman]

You showed a picture of the gas key stating that it was "over staked". Have you tried to tighten it? I had one that looked like it was staked properly on a gun that I couldn't get to cycle. I checked/changed everything (spring, buffer, gas tube) to try to get it to work, nothing. For the heck of it I checked the gas key, it was loose. Tightened it down, re-staked and she ran like a top. Worth a try if you haven't done so.

 

[Gun Nut]

Staking on the gas key is ****ty. Try to untighten it at 30 inch lbs. If it comes lose at 30 inch lbs get a new gas key and better screws and restake the key. Look at the key if you do remove it and see if it is leaking. If it doesn't loosen at 30 inch lbs run a small piece of wire down the gas key to see if it comes out in the carrier. Hope this helps other good info on post also.

 

[greg vess]

Make sure the ejector is not to long. I've seen that problem before. That won't allow the rim of cartridge to slide all the across the bolt face. Also make sure extractor isn't to tight. I seen where that won't grab the cartridge and it will stop it about an inch and half from going into battery. Take the oring out of the extractor. See if they helps. If there is to much grease in the buffer tube is a light coat and not a big glob. That will get really thick in colder weather. It work fine in the summer and seize in the winter months. It could also be a out of spec bolt.

 

[GunTech]

Your extractor is bad...either chipped, weak spring, or missing the rubber ring or possibly dirty. But if all the other things were checked as stated in previous post, your extractor is the culprit which would cause your issues. Take your extractor from your good bolt and put in this bolt to see if it eliminates the problem. possible ejector spring is broken. Take a punch and press in on the ejector to make sure it compresses in with a fair amount of resistance.
If you have dummy rounds, load some up and cycle thru the firearm.