bishop333 Posted December 24, 2017 Report Share Posted December 24, 2017 Hello All, Just received Shilen 308 barrel blank for an AR10 build. Have the barrel extension as well. Dobe several ar15 barrels but first ar10. However, cannot for the life of me find the drawing/dimensions for the trunnion threads and length? I believe the threads are 1-16 but need the length as well as some of the other minor dimensions. Anyone have drawings for the AR10 barrel trunnion area? Thank you, first post so here I go into the ar10 world..... Quote Link to comment Share on other sites More sharing options...
98Z5V Posted December 24, 2017 Report Share Posted December 24, 2017 (edited) 30 minutes ago, bishop333 said: Have the barrel extension as well. "AR10" is pretty commonly used, and shouldn't be, for a very specific reason. What's the pattern on your extension? Edited December 24, 2017 by 98Z5V Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted December 24, 2017 Report Share Posted December 24, 2017 The SR-25, LR308 and AR-10 format rifles all use a 1:16 TPI barrel extension. Quote Link to comment Share on other sites More sharing options...
308kiwi Posted December 24, 2017 Report Share Posted December 24, 2017 DPMS pattern extension has a 1" major dia thread, 16 TPI Trunion length is easy enough to figure out, locate the bolt into the barrel extension, sit the back of the bolt lugs against the front of the barrel extension lugs, measure with a depth micrometer from the front face of the barrel extension to the front of the bolt, this measurement is going to be your clearance for the bolt lugs between the breech face, (end of the barrel) and your bolt. Make sure whoever cuts the thread relieves the thread at the shoulder on the barrel where the extension will lock up against, you will also need to machine the first couple of threads down to their minor dia to clear the end of the thread in the barrel extension. Quote Link to comment Share on other sites More sharing options...
308kiwi Posted December 24, 2017 Report Share Posted December 24, 2017 8 minutes ago, 308kiwi said: clearance for the bolt lugs between the breech face, (end of the barrel) and your bolt. Sorry that should read......clearance for the bolt lugs between the breech face, (end of the barrel), and the front face of the barrel extension lugs. Quote Link to comment Share on other sites More sharing options...
shepp Posted December 24, 2017 Report Share Posted December 24, 2017 1 hour ago, bishop333 said: Hello All, Just received Shilen 308 barrel blank for an AR10 build. Have the barrel extension as well. Dobe several ar15 barrels but first ar10. However, cannot for the life of me find the drawing/dimensions for the trunnion threads and length? I believe the threads are 1-16 but need the length as well as some of the other minor dimensions. Anyone have drawings for the AR10 barrel trunnion area? Thank you, first post so here I go into the ar10 world..... 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...
bishop333 Posted December 24, 2017 Author Report Share Posted December 24, 2017 Thanks guys, helpful and gets me started. I did find a drawing for the trunnion for the AR10 as well (attached) and it fits the description you guys gave here. So looks like I am good to go! Let you know how it goes. Thank you. Quote Link to comment Share on other sites More sharing options...
shad Posted September 21, 2020 Report Share Posted September 21, 2020 could you have blue print of barrel extension... Quote Link to comment Share on other sites More sharing options...
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