Here’s a build that was started 2-3 years ago. I had built a mini30 into a M1a lookalike [camo rifle photo] after my retirement so I researched rebuilding the Ruger mini into a T20 Garand. The T20 was an experimental 20 rd box magazine fed, select fire version of the M1 garand. They never could get the .30-06 version to work but the Italians did it with the .308 BM-59. Anyway I found a guy who had done it on the FalFiles forum but he wasn’t very much help. Did that deter me, nah. My donor rifle was an older mini14 .223 with the garand style rear sight. I had Accuracy Systems install a 300blkout, 24 inch bbl machined to the garand bbl’s outside dimensions. I then inlet that much into a garand stock. The garand action is 9 in long while the mini is only 6 in so there was a lot of jbweld and walnut inserts to get it to fit. I also installed the Ruger steel reenforcement. The next thing was figuring out the op rods as the rear half was the ruger op rod while the front would be a garand rod to fit into the gas cylinder. And of course the upper handguard. After a couple of false starts looking for someone to install the gc I finally found a semi local smith/machinists who could do the work.
The gas cylinder fit on my bbl fine, so my smith cut the spline slots and threaded the bbl. He also cut the two op rods, fitted them to the action and cylinder and welded them together. He tinkered with the op rod spring and spring guide but couldn’t get it to cycle factory loads. At this point I got it from him and I started playing with it. I eventually opened the gas port up enough and modded the op rod guide and spring until it will run. This is the condensed version of this story.