U-Channel Caliburn Build and Review

Editor’s note: This other Brian guy keeps building and writing things. I should probably make him account at some point…Also, it comes at a time when I’m busy, and having a second Caliburn opinion never hurt. Especially for a different setup!

Hey everyone! It’s Brian’s ghost writer here (also Brian).  I had the pleasure of assembling a Rival U-Channel Caliburn when the hardware kits went on sale for cyber Monday.  I wanted a rival Caliburn because I have Caliburns that shoot harder than 200 fps, and a multitude of blasters for hvz/low fps games, but nothing that sat in the middle.  Also, owning a Jupiter, I wanted another excuse to bring Rival magazines.  I figured a Rival U-channel Caliburn would also be useful as my difficulties could help air out issues that lead to revisions so future U-channel Caliburns are more functional.


I purchased a hardware kit with k25 spring and metal ramrod from Captain Slug, and had a friend print me the 3d printed parts. All parts were printed at 20% infill and they seem to be holding together.  Assembly was very intuitive just by looking at pictures and occasionally following along with the instructions.  I only had the Elite U-channel Caliburn instructions to work off of, but it was more than enough.  Sometimes I needed to put my weight onto a part to seat it into the right spot along the U-channel but ultimately everything went together with ease. The U-channels make it less wobbly in the middle unlike a traditional Caliburn that uses six threaded rods and is divided down the middle.  These channels do not flex, and the screws so far have not gotten loose.  Since there is only the barrel, bars, and U-channels, the pump grip does have maybe 15 degrees of rotation around the barrel but this isn’t hindering performance at all. It’s just slightly strange, and could probably be fixed with an upper rail.


Well, with a k25 spring and metal ramrod, it goes THOOMP right in my ear and I never grow tired of the sound.  It is advertised to hit 160 fps with metal bolt and k25. I don’t have a chronograph to test that, but I do know that with the hop up, denser rounds can travel up to 90 feet, and less dense shots and shots without hop-up travel about 60 feet and then promptly dive into the earth.  Accuracy does escape this blaster past 50 feet however.  Maybe I just need to get better with the hopup and use more consistent ammo?  Maybe a cool trick shoot would be firing parallel to the ground and seeing if you can hit a target ten feet in the air, and maybe two feet in either direction?

Final Thoughts

It’s a bit hefty with the U-Channels, but the rigidity is well worth it. Assembly will be as easy as your prints are precise.  I can’t wait to see what comes of the U-channel caliburn designs in the future.  I do recommend a U channel caliburn if you are on the fence about whether to do that or traditional caliburn, regardless of ammo type.  Maybe wait a bit for the designs to be more refined, but if you’re itching for one RIGHT NOW, you won’t be disappointed.

For $120 I was able to get the parts and the kit from the various sources, which I think is well worth it.

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