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Posted: 11/26/2025 2:28:41 PM EDT
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I had a new PSA 10” pistol upper that was running 100%. I decided to install a Law Tactical folder and since then the bolt sticks and won’t fully close. I removed the LT folder and found I still have the problem of the bolt sticking. I tried a different BCG and it didn’t help. When I try to eject a full magazine manually 1 or 2 will eject then the BCG will get stuck about 1/4” from fully forward. I have to mortar to free up. I cleaned the chamber throughly, no change. I’m going to the range again today with a different upper and BCG to troubleshoot. I can manually drop a round in the chamber without a problem. WTF? Bad upper receiver maybe? ?? |
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Any info you could provide about the rifle, like brand of lower receiver, type of buffer and buffer spring used, charging handle, etc, as this may help give us an idea of what you are working with? Any chance you could post a pic or two , specifically looking forward from the back of the upper receiver that would show the barrel extension lugs. Can you manually cycle the action when it is not loaded, and does it stick then as well? How about if you insert just the bolt carrier by itself with no bolt or cam pin to see if it moves freely? When you shoot it, are there any markings on the expended brass casings that would indicate things are sticking as in a rough or out of spec chamber? CY6 Greg Sullivan "Sully" WeaponsArmorer SLR15 Rifles Defensive Edge Training (763) 712-0123 |
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Originally Posted By sully: Any info you could provide about the rifle, like brand of lower receiver, type of buffer and buffer spring used, charging handle, etc, as this may help give us an idea of what you are working with? Any chance you could post a pic or two , specifically looking forward from the back of the upper receiver that would show the barrel extension lugs. Can you manually cycle the action when it is not loaded, and does it stick then as well? How about if you insert just the bolt carrier by itself with no bolt or cam pin to see if it moves freely? Upper is all PSA. After further checking I found that I can manually load 1 round at a time and it ejects fine. With a mag installed the bolt jams and I can’t eject even 1 round. I tried 2 different P mags and have the same problem. |
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I took the BCG apart and lubed it. I loaded 1 round at a time (no mag) and it ejected fine. I put a mag in with 10 rounds and it ejected 3 rounds fine then the bolt wouldn’t go back to eject the 4th round. Had to mortar it. What’s puzzling is the gun ran fine until I installed the Law folder. I don’t think the folder was the problem. Attached File Attached File Attached File |
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Originally Posted By racer765: agree - is the buffer retainer pin damaged and dragging on the buffer? Appears fine. Attached File |
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I'm staring at this pic. I've saved it and tried to enhance the lighting and exposure and contrast And I tried to recreate the same pic. Angle lighting zoom etc Your hammer face looks odd. All 4 of mine I looked at that surface is almost flat. And the wear of the finish doesn't look anything like on your hammer and The disconnect I can't tell if it's installed correctly. Hook that grabs the underside of the hammer should be pointed to muzzle Ask yourself: As the bolt moves fwd and back what is putting pressure causing drag on it to slow it down and prevent full range of movement? Do you have another lower to try? This is an 80% completed lower? Originally Posted By BlackdogADV: I took the BCG apart and lubed it. I loaded 1 round at a time (no mag) and it ejected fine. I put a mag in with 10 rounds and it ejected 3 rounds fine then the bolt wouldn’t go back to eject the 4th round. Had to mortar it. What’s puzzling is the gun ran fine until I installed the Law folder. I don’t think the folder was the problem. Attached File |
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Originally Posted By Laserjock:Your hammer face looks odd. I noticed that too. Like it's worn on one side. Also though, it looks like there is NO wear on the bolt catch. Like it's brand new. But he says this whole build ran fine before the Law Folder. He had this bolt sticking issue, removed the folder and went back to the original setup with everything the same, but the problem persists now. He has to mortar it to get it loose. I certainly don't know near as much as a lotta guys around here, but I can't make any sense out of that. It seems like some piece of information is missing. |
| I took it out today and it ran fine. 30 rounds, no problem. Only thing I can think of is a piece of debris was in the chamber. I checked the chamber numerous times and didn’t see anything. Still I’m reluctant to certify it for war until I can trust it. This was driving me nuts. |
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Going back and looking at all of your descriptions of what is happening, from what I understand is the the rifle functions as far as you can load, then fire it, then the bolt carrier assembly has no issues unlocking from battery, then as the bolt carrier assembly travels rearward it has no issues extracting and ejecting the empty casing after firing just fine. But the problem happens when you install a magazine with multiple rounds in it, where from what I am understanding is that after a couple of rounds running just fine, that all of a sudden the bolt carrier assembly only goes rearward about 1/4" and then gets jammed up, so now you have to mortar the gun to get the bolt carrier assembly to go to the rear and extract the fired cartridge from the chamber and then the action will continue rearward and eject the formerly stuck fired casing, is this correct? If this is what is happening, then I would suggest trying a one shot at a time to see if the same problem exists or is different. The one shot diagnosing method is this, load one round of ammunition into the magazine, inserting the magazine and confirm that the magazine is locked into the magazine well, then manually cycle the action to get it to load and lock into battery, then fire the one live round and let the gun cycle to see if it will correctly unlock, extract the empty casing, eject the empty casing, and lock back on the empty magazine. Repeat this several times to see if the gun cycles correctly, of what results you get. Also from the previous issues, are there any markings on the fired casings, or newly loaded ammunition after you manually extract and eject it so see if there are any markings or deformation on the casings or bullets that may help tell us what is happening. Have you tried different new factory ammunition from reputable United States Manufactures like Federal, Speer, Hornady, Black Hills, Winchester, Remington, Fiocchi. etc? Next diagnosis, if you have a different rifle, maybe try the upper on a different lower receiver to see if the result change. This will help diagnose if the problem is with the lower receiver, or possibly the upper receiver assembly. Looking at a few of the pics, it is hard to tell but it appears to me that this lower is an 80% that was machined out. If this is the case, I would suggest dropping the upper on a different lower receiver to see if things change. The top of the receiver in this pic, specifically in the area just above the safety selector, if you look on top there is some metal sticking up on the right side that is semi-circular in shape that is not or the left side, making me wonder if the machining is out of spec and this would make the upper receiver diagonal as compared to the lower receiver.  Another possible issue I have come across is a bent buffer tube, or an out of spec buffer tube threading on the receiver, where the buffer tube is off center or diagonal, which is causing the bolt carrier to not ride flat and centered with the bore of the barrel, usually I have found this by looking at the problem casings and ammunition for markings. CY6 Greg Sullivan "Sully" WeaponsArmorer SLR15 Rifles Defensive Edge Training (763) 712-0123 |
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Originally Posted By Laserjock: This is an A 95% of the way completed lower There's a web between the safety and rear take down holes that were NOT cut out. See last quoted pic Didn't notice that before Originally Posted By Laserjock: This is an A 95% of the way completed lower There's a web between the safety and rear take down holes that were NOT cut out. See last quoted pic Didn't notice that before Originally Posted By BlackdogADV: I took the BCG apart and lubed it. I loaded 1 round at a time (no mag) and it ejected fine. I put a mag in with 10 rounds and it ejected 3 rounds fine then the bolt wouldn’t go back to eject the 4th round. Had to mortar it. What’s puzzling is the gun ran fine until I installed the Law folder. I don’t think the folder was the problem. |
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When I went to the range I had another complete operational rifle along with another proven upper. That way I could mix parts to get it to run and it wouldn’t be a wasted trip. As it turned out it ran fine. I wasn’t expecting that. Also, this batch of lowers all had the semicircle mark on top. The web between the safety and rear takedown pins were left intentionally. Sometimes I cut them sometimes not. |
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EE: 100% (16)
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Check out your bolt. Is your ejector pin fully extended? (Compare with another bolt that has been flawless.) Maybe the spring in there has debris in it somehow that is not allowing full extension of spring? I have a bolt with a problem ejector, where it was no longer returning to "zero" and that bolt wouldn't fully chamber a round. I just ordered a new ejector, spring, and roll pin. People have also recommended changing out the O-Ring under the extractor, as sometimes they can harden and now allow the extractor to move as intended. Just some other things to check out. |
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| The common denominator here is that you messed with the buffer. Looking at the pictures, I would say the buffer tube does not appear to be threaded in all the way and the castle nut does not look like it was torqued at all. My thought is the problem is the buffer tube isn't in all the way. It's working sometimes but not others and that would explain why it can't get fully into battery because there simply isn't enough spring pressure to make the bcg fly home. Stripping a round from the magazine requires some considerable force and not having enough spring power behind it could be why it's not able to get into battery. |
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One other thing it could be that I haven't seen mentioned yet is the magazine feed lips contacting the belly of the carrier. To test this, disassemble a suspected magazine, then insert it into the lower while keeping upward pressure on the mag, then try to slowly cycle the action and visually check for interference. |
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