Buffer tube sizes. [Archive] - Glock Talk Glock Talk > Go Ask The Expert Forums > GATE AR-15 Forum > Buffer tube sizes. PDA View Full Version : Buffer tube sizes. wolf19r02-06-2011, 23:34I am building my first AR on a stripped Rock River lower and was wondering if a mil spec buffer tube would fit the threads cut on the lower receiver? Thanks Constructor02-07-2011, 23:04All of the threads are the same only the diameter of the tube is different, just match the tube with the stock. wolf19r02-08-2011, 14:45Thanks vBulletin® v3.8.7, Copyright ©2000-2015, vBulletin Solutions, Inc.