AR Sponsor
Posted: 6/25/2026 6:08:09 PM EDT
|
What’s wrong with this guy? Is he too good for his home? It ran fine as a binary. It ran mostly fine with a super safety. Still runs fine in semi. Now it’s doing this in super. It gets close, but not quite all the way closed. It’s an Atrius with a Rave 140, Spingco blue and Spike’s T2 buffer. This is as close as it gets most times. Attached File |
|
The thing is, the bcg is just stopping completely. You can’t force it forward with the forward assist or by thumb. Something is hitting solid. It is the same thing on a function check with zero ammo in the equation. I’ve experienced insufficiently heavy buffers. This isn’t acting like that at all. It started doing this a while back and I just put it in the safe and forgot about it. I was hoping to read something about the condition here but haven’t. The bolt is very smooth engaging the lugs until super. It feels like trying to chamber an overly long round. I can’t find any shiny spots where it looks like something is hitting. I discovered something else messing with it. Sometimes when I can get it to close properly, the trigger is stuck. The hammer will be back and properly locked, but you cannot pull the trigger. When I swing it open and look, the hammer is cocked and ready to go. Opening and shutting the receivers lets the trigger be pulled and the hammer will fall. |
|
The cam lever may be binding on the rear of the upper receiver. Do you try the binding test on the Atrius troubleshooting page ? I had a SS that was hitting the back of the upper receiver causing the bolt to lock up. I fixed it by adding a couple of quarters in the buffer tube before the spring that prevents the bcg from traveling too far into the tube. |
|
Originally Posted By MereMortal: The cam lever may be binding on the rear of the upper receiver. Do you try the binding test on the Atrius troubleshooting page ? I had a SS that was hitting the back of the upper receiver causing the bolt to lock up. I fixed it by adding a couple of quarters in the buffer tube before the spring that prevents the bcg from traveling too far into the tube. I had a Kabuto doing exactly that. I was cheap and tried to fix it with a single quarter but it took $.50 to fix it. It was much further back than this. Mocking it up, it appears the bolt would be much further forward. Enough to make that scenario impossible. Also, with the Kabuto it made distinctive marks on the bolt carrier. On one I Dremeled off the little edge as it is milled with a curve that rotates slightly forward in the middle. With a slight bevel the lever goes up and inside the carrier. |
|
I saw a video about the stuck trigger issue. I was able to find it in my history. Try this, it may help. Could the hammer be causing the bcg to lock up and not the cam lever? I have an idea of what might be causing it, but due to a migraine I'm having a hard time trying to explain it. I'll try something on my setup in the morning based on what is in the video above. |
|
Thank you. I was hopeful that was it because it is very tight in there. It’s not quite the same with the cassette trigger, but it’s very close. Sadly, no. I noticed something that will probably help somebody smarter than me solve it. As soon as I open the receivers with pressure on the trigger, the hammer will fall. I haven’t done anything to the BCG. On a couple of the Kabutos I beveled the BCG edge that would contact the lever. Maybe I need to try another carrier. |
|
I found something today after installing my setup into a Kuna with a Nexus lower. While doing a function check on the third position, I pulled the trigger, dropped the hammer, and with the trigger held back and the cam lever forward near the trigger it took a lot more pressure than I thought it should for the hammer to latch onto the disconnector. Instead of a nice easy click it was more like a hard thud. I'm wondering if it is possible that the hammer is not latching on to the disconnector, binding in the trigger and is somehow jamming the bcg. I guess any odd rubbing between the hammer and bcg would be hidden by normal wear. Without the hammer being latched it would also fall when the upper and lower are separated. Will the hammer fall if you're not pulling the trigger when separating the upper and lower? |
|
Originally Posted By MereMortal:. Will the hammer fall if you're not pulling the trigger when separating the upper and lower? Nope. So I think it shouldn’t be hard to understand for someone here. The hammer stays cocked. Separating it allows for the trigger to be pulled as normal. This is only in assisted. It’s fine in semi. So I think it has to be related to the position of the lever. Maybe something is out of spec? I’ll find another BCG to try in it. The one I bought was a discounted blem. Actually many parts in it are the cheapest I could find. Didn’t want to hesitate to play with it and it was supposed to be somewhat disposable. Really like the Kinetic lower though. Was gonna make a bump saw but they were made unobtainable right after I got it. ETA Jealous of your Kuna. That sounds like the most fun 9mm at this point in time. About the vitiligo, I tried airbrushing camo stencils with a dark green border. I should’ve used black. Next time maybe. |
|
I have to agree with you that it probably has to be with the lever, it's the only thing that makes sense at the moment. It could be out of spec or everything is on the high side of specs and causing the issue. My setup had some binding issues at first and I ended up taking a little off of the trigger bar using 220 and 600 grit diamond sharpening stones, and polishing it with a ceramic stone. The Kuna is fun little gun. Not as smooth as an MP5, and it can be a little gassy but it is cheaper to shoot especially with a FRT. |
|
My Atrius lever kept finding its way into the groove of the carrier. The selector would bind, sometimes re-racking the charging handle would get the lever back into place. It ended up bending the lever over messing with it and would not work. At first glance it looked fine, but I had another to compare it to. The bent one was almost 90 degrees. I'd swap carriers and check the lever to see if it got bent. |
AR Sponsor
Join the Community
Your next conversation starts here.
Create your free account to join discussions, share your experience, save topics, and connect with the AR15.COM community.
- Join discussions
- Follow topics and replies
- Connect with fellow enthusiasts
Already a member? Sign in
Stay informed by subscribing to our Newsletter