Simply put, what is required? Looking at this ramped barrel https://www.ebay.com/itm/262976418164, figure also need new 9mm recoil spring and magazine, wondering if the barrel bushing is the same? Is there more to it than that?
First, I'm not at home to check
Second, I have a RIA in 9mm and 45. And from what I can remember, the OD of the barrels look the same.
Again, I'm not at home to check
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Have you considered selling it and buying a factory 9 mm 1911? I'm pretty sure you could move it right now. Even though 9 mm 1911's are outselling .45's by a considerable margin.