Open Source Arms maintains an open technical database of standardized testing, manufacturing practices, and technical data packages of tested firearm designs.

Joined August 2026
Right click, Add Pause.
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Open Source Arms retweeted
Time the print so that stage happens while you're sitting right next to it, so everything stays hot. Maybe even keep your inserts on the floor of the printer so they're warm when you insert them instead of cold-shocking your print.
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Getting better all the time.
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Print in Place insert.
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Sheesh. #2 Chassis ready for printed parts.
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Open Source Arms retweeted
I guarantee this is the weirdest gun you’ll see today. Featuring the new 9mm hush puzzle.
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Open Source Arms retweeted
Now with candy corn baffles in PLA orange
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We are pretty close to a flawless fit, very satisfying.
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Worked that mismatch with a file, then a stone, and then a surface plate with sandpaper affixed with gaffers tape on one edge so the other edge could be supported by a right angle block.
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OSA-15 Build Update.
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One final change before releasing the OSA-15 upper. We're revising the trunnion to incorporate a metallic feed ramp. The previous polymer design worked, but long-term durability matters. If you're investing the time to build it yourself, it should be built to last.
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Trunnion prepped for fit and final rivet within the upper.
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Open Source Arms retweeted
As a mockup, this goes extremely hard, but I would need to find a 9mm mag body that can fit within the mock ak mag to make it feed right
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A little bit every day makes the rifle just around the way.
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Put the work in and then...
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Cleaning up the trunnion.
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You get an SBR, you get an SBR, you get an SBR.
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You would want the Carbine length, or Pistol Length upper.
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Same.
me in my garage this afternoon with a 6 pack of PBR
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