{"id":9185,"date":"2018-05-10T03:14:49","date_gmt":"2018-05-10T02:14:49","guid":{"rendered":"https:\/\/gunsmithdesigner.com\/?p=9185"},"modified":"2026-11-12T15:42:05","modified_gmt":"2026-11-12T14:42:05","slug":"ruger-mk-ii-barrel-disassembly-and-reassembly","status":"publish","type":"post","link":"https:\/\/gunsmithdesigner.com\/index.php\/2018\/05\/10\/ruger-mk-ii-barrel-disassembly-and-reassembly\/","title":{"rendered":"Ruger MK II, barrel disassembly and reassembly"},"content":{"rendered":"

While looking for answers to my questions on an American forum, I came across a series of posts regarding a user’s wish to replace the barrel of his Ruger MK II pistol, who was unable to find the operating procedure to carry out this task.<\/p>\n

This made me want to research this information and make it available to the community. Since if you want a thing done well, do it yourself\u2014and you can only believe what you see\u2014I preferred to gather this information directly at the source, right at the workbench, rather than simply relaying details found online.<\/p>\n

\"\"<\/p>\n

<\/em><\/div>\n
<\/div>\n

Tooling<\/strong><\/h2>\n
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    • As seen in a previous article, it is not always easy to find the right equipment for a specific job. This is once again the case for the Ruger pistol. While it is possible to find the die to recut or clean the barrel threads, I have never seen a receiver wrench or interface specifically made for the receiver for sale. Therefore, I had to make one myself. This fixture is designed to fit onto the front of the receiver. It uses the flat surface on the underside of the receiver as a bearing surface for tightening and loosening. I chose not to use the ejection port cutout or the rear bolt notch to avoid any risk of damaging or twisting the receiver.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

      \"Ruger<\/p>\n

      <\/p>\n

      <\/em><\/div>\n
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        • Two wrenches, which will be used to secure the fixture onto the receiver.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

          \"Ruger<\/p>\n

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            • A torque wrench to measure the breakaway torque. Here, I used a W\u00fcrth model ranging from 20 to 100 N\u00b7m (approx. 15 to 74 ft-lbs). The part number is visible below.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

              \"Ruger<\/p>\n

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                • A rigid anchor point to firmly hold either the receiver or the barrel. Once again, I chose to mount the fixture onto the receiver and clamp the barrel into the fixed point. Doing the reverse would also be possible. My rigid anchor point is a milling machine\u2014or more precisely, the machine’s vise.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

                  <\/p>\n

                  \"He<\/em><\/p>\n

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                    • Two aluminum V-blocks to protect the barrel.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

                      \"Aluminum<\/p>\n

                      <\/p>\n

                      <\/div>\n

                      Pre-Disassembly Steps<\/strong><\/h2>\n

                      Before disassembly, the area where the barrel threads into the receiver (the breech\/chamber area) was heated with a blowtorch. The purpose of this is to detect whether threadlocker or adhesive was applied by the manufacturer when installing the barrel. Heating this section\u2014if the parts were bonded together\u2014produces smoke and a distinctive odor. This provides extra insight into what to expect. It also serves to burn off the adhesive and break its bond.<\/p>\n

                      The actual removal of the barrel was performed cold.<\/p>\n

                      <\/div>\n

                      Installing the Fixture<\/strong><\/em><\/h3>\n

                      \"Ruger<\/p>\n

                      Once the fixture is installed, a very slight clearance remains between the jig and the receiver so as not to compress the receiver inward and risk damaging the barrel threads.<\/p>\n

                      \"The<\/em>Disassembly and Torque Measurement<\/strong><\/h3>\n

                      <\/h3>\n

                      Determining the breakaway torque is done empirically by testing a low setting on the torque wrench and gradually increasing the value between attempts. This method provides:<\/p>\n

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                        • An estimate of the factory tightening torque ;<\/span><\/li>\n
                        • An estimate of the torque required for reassembly.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

                          <\/p>\n

                          This is a technique we already covered in the articles on removing and reinstalling a Winchester 94 barrel (link here<\/a> and here<\/a>).<\/p>\n

                          One could skip recording this value and do without a torque wrench. However, it would be a shame to miss out on valuable and rarely documented technical data.<\/p>\n

                          A video demonstrating the procedure is available below.<\/p>\n