gsmopar Posted March 29, 2013 Report Share Posted March 29, 2013 3rd time out with the .308 and I ran into the same problem as the last time. I can use some advice on a couple topics: The gas block loosened up again causing the gun to jam. I could fire a couple rounds, reach up and push the block back in place and continue for a couple more rounds. This time when I got the rifle home I loosened both set screws (already loose, similar to my last outing), and slid the block further up the barrel exposing the gas port. I noticed a divot in the barrel that looks like it is meant for the rear most set screw to set in to keep the block in place. This time I aligned the gas block with the divot and used Locktite on both set screws. Please let me know if this is common, or am I doing something wrong, etc... My Heavybuffer arrived in the mail today! While removing the old buffer I noticed that it is damaged along the edges where the buffer contacts the spring loaded recessed retaining pin. I'm going to do some youtube searching, but I guess that I have the same questions as above. Is this normal, etc... I can post some pics if you guys need them to help diagnose. I think that the gun shoots pretty straight. It would be nice to sight it in and be able to quit messing with the scope, but that won't happen until I stop removing it to work on the gas block. All shots are at 100 yards. Thanks for the help!!! Quote Link to comment Share on other sites More sharing options...
98Z5V Posted March 29, 2013 Report Share Posted March 29, 2013 1. Having the gas block loosen up on you is not normal. However, only having one recess drilled in the barrel, for the rear-most set screw is normal. Using red loc-tite on those set screws is routine - should be done. 2. Get pics of that old buffer face - I know where this is going, already. Get some pics of it up, man. What upper and lower did you use on this build, again? Quote Link to comment Share on other sites More sharing options...
imschur Posted March 29, 2013 Report Share Posted March 29, 2013 and you can get someone to pin that block in place too Quote Link to comment Share on other sites More sharing options...
gsmopar Posted March 29, 2013 Author Report Share Posted March 29, 2013 1. Having the gas block loosen up on you is not normal. However, only having one recess drilled in the barrel, for the rear-most set screw is normal. Using red loc-tite on those set screws is routine - should be done. 2. Get pics of that old buffer face - I know where this is going, already. Get some pics of it up, man. What upper and lower did you use on this build, again? The upper is CMMG. The lower is from Quentin Defense in Gilbert AZ. The upper I purchased as a complete assembled upper. The lower was stripped and I put it together with a CMMG lower parts kit. Quote Link to comment Share on other sites More sharing options...
planeflyer21 Posted March 29, 2013 Report Share Posted March 29, 2013 At first glance, that buffer looks like a chewed up penny. I don't know but if I had to guess, it looks like the buffer retainer pin isn't held as deep as it should be. Like the buffer is slamming into the larger diameter portion of that pin. Which seems like it would interfere with the boltcarrier travel as well. This uneducated guess has been brought to you by Kroger's Medium Roast Coffee and Orowheat homemade cinnamon toast. Jon Quote Link to comment Share on other sites More sharing options...
imschur Posted March 29, 2013 Report Share Posted March 29, 2013 I was going to guess CMMG or IRA Quote Link to comment Share on other sites More sharing options...
98Z5V Posted March 29, 2013 Report Share Posted March 29, 2013 I knew it. The back of the BCG isn't pushing the buffer off it's retaining pin when you close the upper and lower together. That's what is chewing up your buffer face. This is very, very similar to the early issues with the IRA sets. There's something off in the machining, with the upper receiver, lower receiver, or bolt carrier length. One of those three. I'd be very hesitant to find the fault with the Quentin Defense lower - those guys have been putting out very high quality parts for a very long time, and really know what they're doing. Short answer in all this - you can solve this problem for about $60. Insert a Tubb CWS into the bolt carrier, as it adds 0.080" to the length of the carrier. That should be enough to push the buffer off it's retaining pin, when upper and lower are closed. Quote Link to comment Share on other sites More sharing options...
imschur Posted March 29, 2013 Report Share Posted March 29, 2013 There was some talk of CMMG BCG's not being proper length Quote Link to comment Share on other sites More sharing options...
gsmopar Posted March 29, 2013 Author Report Share Posted March 29, 2013 Thanks for the replies! This hobby is almost as expensive as my Hot Rod hobby. I did some web surfing and found articles on AR15.com and a few other forums. Some of the threads that I read suggested similar to what 98Z5V stated above in his reply. When I went to inspect my rifle my Buffer detent pin broke at the tip. I suspect that 98Z5V's diagnosis is correct and my buffer was hitting the pin rather than resting against the BCG. I ordered a Tubb CWS and a new detent pin. I also got some additional suggestions from Dane Armory in a PM. Will I have a problem running both the Heavy Buffer and Tubb CWS? Thanks, Greg Quote Link to comment Share on other sites More sharing options...
98Z5V Posted March 29, 2013 Report Share Posted March 29, 2013 The CWS is a shell and two differently-weighted inserts. You can run just the shell, and no weights. What you're after is the 0.080" added onto the length of the carrier. <thumbsup> Quote Link to comment Share on other sites More sharing options...
unforgiven Posted March 29, 2013 Report Share Posted March 29, 2013 <munch> You'r in good hands here brother. Quote Link to comment Share on other sites More sharing options...
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