I have a PSA gen2 upper and lower PA-10 with a Faxon barrel and Ballistic Advantage BCG. The receiver extension & buffer is PSA’s PA-10 version. I fired for the first time this weekend and got about 2 rounds off before the BCG stuck to the rear, locked open. It is binding on something, but I can’t tell exactly what. Its not the Bolt catch, as you can see in the pics, its a good bit further back to the rear and the catch isn’t coming into contact at all. I disassembled everything to see if there were any noticeable wear marks anywhere, and say some strange marks on the threads on the receiver, but nothing corresponding on the BCG.
Any ideas on where to start troubleshooting? Im stumped here…
Don’t be surprised if you have a blown primer somewhere that is potentially lodged between the upper and BCG. I also seeing something strange in Pic 1 at about 1:30.
Here is my wild guess. It is hard to tell from the picture, but in the pic of your lower receiver, the threads look destroyed in two spots. The spots look white like bare aluminum. And there appears to be a white powder nearby. Is the carrier hitting those two spots? If the carrier is traveling too far back maybe that would cause the bearing surfaces of the carrier to hit the threads in that location and bind. I’m not familiar enough with ar-10’s to know if this is possible before the gas key would hit the lower. If this is happening maybe your buffer is too short.
This was is EXACTLY. The carrier was the stubby Pa-10 version (I’m guessing for use maybe if it is a 5.56 tube) and when I took the spring out, you could see that the BCG was wedging into the threads. I swapped a standard buffer out of one of my 5.56 guns and it’s cycling fine now. The buffer was too short. Thanks guys!
Yes, agree with over-travel. Surprisingly the quarter trick works very well. Have had this happen before for with a previous build.
+1 on the A5 buffer tube and the H3 buffer for an optimal carbine setup.
The other problem with too much over travel is that it is really hard on the bolt catch… As the bolt slams forward, the larger 308 BCG mass along with a stronger buffer spring place ALOT of load on it. I figured this out only after the failure of 2 bolt catches.
It’s too bad that we live in a world that “easy” normally isn’t better or best. Unfortunately, “easy” normally means a band aid in this industry rather than addressing core issues. Adding something that would not have to be there to begin with to address an issue with the base product is not as preferable of a solution than one that alters the base product to not require them to have a band aid to begin with.
Just look at all the crap the market is saturated with now, oversized based gas ported barrels, some really poor cans touted as superior, triggers you can’t rely on, etc…
There’s only so many band aids that could be applied over each other before a reasonable person could make a stronger argument that a base that did not require those would be more preferable and be very convincing.
Agreed 100%. The Bubba method of correcting someone’s mistake, rather than making someone correct their mistake is why we have so much garbage in the firearms industry and especially the AR market.
When I HAD the Aero .308, I initially used 2 quarters then picked up the Sprinco spring and that solved it without the quarters. I counted the coils on the Sprinco verses stock and it had 2-3 more coils. While I did not break a bolt catch, plenty others have prior to “fixing” the over travel and hitting the rear of the receiver AND having more travel was slamming into the bolt catch with increased force causing breakage.
After I swapped my buffer for the longer one, my issues were gone. The BCG was just slamming into the threads and binding there. I did check the firing pin retainer though, and it looks great for now.
