Waldo

To be absolutely clear: I was experiencing a misfeed/ failure to properly strip any rounds subsequent to the first one from the magazine. If the bolt was locked to the rear manually the first round stripped and fired fine. The next to feed was being caught, lets say approx. 1/3 the way up the case and resulted in a failed feed. It was opined that a gas issue was the culprit and several other ideas which proved incorrect as a fix, Finally what I did notice ( DUH) was that when the mag was empty causing the bolt to catch open, what was occurring was, the catch was actually resting on the shoulder of the BCG vs. the face of the bolt. Once I followed the advice to try the CAR 10 buffer and spring set up I was able to remedy this condition. The buffer and spring on the left is what fixed this issue, the one on the right is what was causing it. Working great ever since.

I had the exact same difficulty. I used the same parts as you initially. The fix was the new buffer spring and using a CAR 10 buffer. It worked for me.

I was bumming for guidance and general knowledge that wasn't (to me) presented in a goofy inconsistent manner. I did a google search and sifted through all the hits until I settled here.

Hey everyone, thanks for the add to this group. I have already learned so much just browsing though the forums and have a long way to go still. I started with two AR-15 builds for my first experience, I was introduced to the 80% lower idea after that, so I chose to break in with two of those in .308. They are now complete and I had to rely on some of the forums here already to get smarter and resolve ( identify) a couple of issues so far. Thanks for sharing your knowledge. Looking forward, I hope to learn as much as I can to become a better craftsman, shooter and just enjoy this new adventure.

Fishing for info / direction on tuning my second ever build. I have an 80% arms lower, using a CMMG .308 lower parts build kit, Palmetto State Armory upper, Radical firearms complete Nickel Boron coated BCG, PSA charging handle, Ergo F-93 buttstock,80% Arms complete .308/ AR-10 Buffer tube kit. Initially, the upper and lower wouldnt close to allow the breakdown pin to be installed. Found upon inspection that the bottom of the charging handle was impacting the lower on top of the ring where the buffer tube screws in to the lower. Very minimal material removed from the lower at the top of that ring allowed the breakdown pin to seat correctly. Now I am experiencing a condition that sometimes the charging handle is EXTREMELY difficult to pull back or impossible to pull back. I thought as described above the handle was being interfered with by the lower, but that isnt the case, thought the bolt when closed was friction fitting very tight but it opens and seats easily when opened up by removing the break down pin. I'm wondering if the BCG isnt somehow interfering/ catching and not mating up with the buffer / buffer tube? when this occurs, wiggling the rifle, turning it over seems to "clear" the obstruction. IDK, Any help or ideas are very much appreciated.

I have a similar issue that I believe I might have identified but not yet resolved. I'm using an Aero precision upper mated with an 80% Arms lower, a CMMG .308 lower parts build kit. I initially thought that I had a failure to feed issue. Releasing the bolt from the locked back position and the first round was not being stripped correctly from the magazine. Instead it was catching the casing approx. 1/3 down the case, stripping it out of the magazine until it jammed up prior to being properly chambered. If you pull the charging handle full back after clearing up the jam, the feed, fire, cycle evolution is fine. Upon deeper inspection I found that the bolt catch is not catching the face of the bolt but instead is stopping the BCG at the BCG forward shoulder instead hence resulting in the bolt face not being in the proper position rearward to either catch and lock open or strip the initial cartridge from the magazine. Viewing without measuring, I can see that when the charging handle is pulled fully rearward, the face of the bolt is requiring approx another 1/16 - 1/8 of an inch of rearward travel to catch. This is all I get though. Looking at these threads has pointed me towards looking at the buffer and buffer spring. Hope this helps someone and if anyone has a comment for something easier / better to try, I'm open to any suggestions.

Just checking in for the first time after making an account. Thanks for this Forum, I need it to become better educated. Now off to the races! Need to resolve a couple issues with my current build. Thanks again!