micu98 Posted July 16, 2017 Report Share Posted July 16, 2017 have newly built 6.5cm with a 20 in ballistic advantage barrel on an aero precision upper and lower. went to the range to break it in, shoots well, ejects and picks up next round without problems. The issue is that it doesnt lock back on the last round. i can manually pull it back and it locks. i forgot to take an extra mag to check it when i went to range (stupid on my part), Any suggestions to check first. could it be the spring, it currently has an orange spring and buffer (not sure of weight) from sons of liberty gun works. i am running an aero bcg and charging handle. I thought it was oiled well but now im not sure. any suggest to check first? Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted July 16, 2017 Report Share Posted July 16, 2017 How many rounds fired? Might be as simple as a few more rounds to break it in. Pictures and measurements of your spring and buffer will help the real Gurus here with diagnoses. Quote Link to comment Share on other sites More sharing options...
micu98 Posted July 16, 2017 Author Report Share Posted July 16, 2017 I only put one box thru it since my range time was cut short. ill have to put picts of buffer tube, buffer and spring later. Quote Link to comment Share on other sites More sharing options...
shepp Posted July 16, 2017 Report Share Posted July 16, 2017 Welcome to the forum feel free to tell us about yourself in the intro section Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 16, 2017 Report Share Posted July 16, 2017 1 hour ago, jtallen83 said: Pictures and measurements of your spring and buffer will help the real Gurus here with diagnoses. 1 hour ago, micu98 said: I only put one box thru it since my range time was cut short. ill have to put picts of buffer tube, buffer and spring later. Make sure you take measurements, as well. Those are more important than pic. What kind of receiver extension? Fixed stock or collapsible stock, rifle or carbine... Buffer length. Buufer spring relaxed length. Number of coils on the buffer spring. Wire diameter of buffer spring wire, if possible. This sounds like a buffer that's not right... Quote Link to comment Share on other sites More sharing options...
survivalshop Posted July 16, 2017 Report Share Posted July 16, 2017 You say newly built , how about spec's on Components used for the build . You say Action functions with feeding & extracting , may need more or different lubricant for low break in round count , run her wet for break in on new build . Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 16, 2017 Report Share Posted July 16, 2017 Gas port diameter as well - but I kinda doubt that on a BA barrel. What bolt catch did you use in this build? Quote Link to comment Share on other sites More sharing options...
micu98 Posted July 16, 2017 Author Report Share Posted July 16, 2017 26 minutes ago, survivalshop said: You say newly built , how about spec's on Components used for the build . You say Action functions with feeding & extracting , may need more or different lubricant for low break in round count , run her wet for break in on new build . all the components in the lower receiver are aero precision, one of their kits. the buffer tube and spring are from sons of liberty gun works. ill post the measurements later when i get home Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 16, 2017 Report Share Posted July 16, 2017 ^^^ That's good - eliminates the bolt catch. The AP bolt catch is slightly different than all the others out there. Quote Link to comment Share on other sites More sharing options...
micu98 Posted July 17, 2017 Author Report Share Posted July 17, 2017 Ok spring is 11 inches with 28 coils. The buffer is 2.5 inches. I don't have a scale that will weigh it right now. It's too heavy for my powder scale. The tube is an adjustable that is 7 1/4 inches. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 17, 2017 Report Share Posted July 17, 2017 24 minutes ago, micu98 said: The tube is an adjustable that is 7 1/4 inches. Is that the internal depth of the receiver extension? Looks like the Sprinco orange spring - not just because of the paint. Length,coil count and wire diameter are right for it. Let's get @washguy to spit out some details on that. Internal depth on that receiver extension has to be 7.000". Not a little under or a little over... Quote Link to comment Share on other sites More sharing options...
micu98 Posted July 17, 2017 Author Report Share Posted July 17, 2017 It is 7 inches. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 17, 2017 Report Share Posted July 17, 2017 Based on the info, if it was mine, I wouldn't look any further into the recoil system then. There's nothing wrong with that combo you've got. It runs. Time to look at gas delivery, and rule out possible issues there. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted July 17, 2017 Report Share Posted July 17, 2017 6 hours ago, survivalshop said: You say Action functions with feeding & extracting , may need more or different lubricant for low break in round count , run her wet for break in on new build . This, too - ^^^ right here. WET. Quote Link to comment Share on other sites More sharing options...
micu98 Posted July 17, 2017 Author Report Share Posted July 17, 2017 I took it apart again to measure and it was dry in some places so I used more clr and applied some tw25 to some of the friction spots on bcg. I try a trip to the range Tuesday and take some oil with me. Quote Link to comment Share on other sites More sharing options...
shepp Posted July 17, 2017 Report Share Posted July 17, 2017 8 minutes ago, micu98 said: I took it apart again to measure and it was dry in some places so I used more clr and applied some tw25 to some of the friction spots on bcg. I try a trip to the range Tuesday and take some oil with me. Get a quart of mobile one synthetic and a squeeze bottle Quote Link to comment Share on other sites More sharing options...
D.R.D. Posted July 17, 2017 Report Share Posted July 17, 2017 Have you tried it again with different mags? Quote Link to comment Share on other sites More sharing options...
washguy Posted July 18, 2017 Report Share Posted July 18, 2017 (edited) Hi sorry for late response if its an orange Sprinco it should be stripping the rounds from the mag with authority compared to regular car308 spring Brand new Sprinco orange spring 28 coils 11.5 inches long Edited July 18, 2017 by washguy Quote Link to comment Share on other sites More sharing options...
MikedaddyH Posted July 18, 2017 Report Share Posted July 18, 2017 On 7/16/2017 at 0:57 PM, survivalshop said: You say newly built , how about spec's on Components used for the build . You say Action functions with feeding & extracting , may need more or different lubricant for low break in round count , run her wet for break in on new build . Also check size of the gasport hole. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted July 18, 2017 Report Share Posted July 18, 2017 1 hour ago, MikedaddyH said: Also check size of the gasport hole. I think you over did the Lube , she has some in the chamber . Quote Link to comment Share on other sites More sharing options...
unforgiven Posted July 18, 2017 Report Share Posted July 18, 2017 That would be the hydraulic effect of said chamber. Quote Link to comment Share on other sites More sharing options...
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