this post was submitted on 12 Nov 2025
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Working on getting my MP22k from GCI running. Basic firing function (stripping rounds, chambering, and firing) is working fine but I'm having some issues with cycling. The biggest problem at the moment is ejection. From what I can tell, extraction is reliable but the casing isn't being properly kicked out through the ejection port. This results in a jam every shot or two. The manual says to start by removing material from the inside of the extractor arm so that it grips the casing more tightly, which I have done but I'm still having the same problem. My current plan is to continue incrementally removing material but I wanted to check if anyone had some experience or insight. Any tips appreciated.

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[โ€“] GunsMiss 1 points 3 weeks ago (1 children)

Few people have built the mp22k and those that have say it's a hard build.

Did you try to film the ejection in slow motion? I think you can get decent details with modern phones.

[โ€“] Aeroiche37 1 points 2 weeks ago

I haven't but I'll try when I get a chance. Honestly, I didnt really have much issue with the build, aside from casting the bolt weight which was a bit of a pain. Really just down to getting reliable ejection and smoother magazine feeding.