Modifications Artemis P15 pellet Probe O-Ring Mod


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This post is specifically about modifying the P15 probe after doing a barrel replacement, but on the general topic of changing from the barrel o-ring to one on the probe, I would highly recommend it. Moving the o-ring to the probe makes it easier to inspect, and change. Barrel cleaning is easier too, not having to worry about removing or just damaging the o-ring with pull throughs.

What I did here, is for my barrel, in my gun, yours could be slightly different depending on the barrel you choose and how you do your leade. I used a .25 23" LW unchoked standard 10 grove rifling .596" diameter barrel(which other parts had to be modified to accept). The dimension for the the leade in the factory barrel was too sloppy to use a probe o-ring setup at .271" so for the new barrel I used a 17/64" drill bit to the exact depth of .5", this put me at .266" which worked beautifully with the probe's diameter of .260". Not having a reamer and the rifling being so shallow, I made my own using cratex rubberized abrasive bits formed to size using a drill, a file, and vernier calipers. The setup took all the time. I used two different grits and ran them in both directions to not have any burs on either side of a land. The time actually using the bits was probably less than 10 seconds x 4 times and then I JB'd it for a while. It turned out perfect. The push through and markings were smooth with both pellets and slugs. Now that I was done with that, the probe itself was next.

There was just enough room to put a double o-ring groove on the probe. I wanted to go double because that was what my Gauntlet used and I new I wouldn't have a problem with getting through the magazines. There is a little trial and error here, even though I had originally figured for a particular o-ring size, on paper, in reality, I had to re-work the groove a little after it was machined in on a lathe, pretty typical. The o-ring size I ended up with was what size fit side by side in the groove that didn't get caught on the magazine. Like everyone else I have bins and bins of o-rings and this was over two years ago and I don't remember. When I have to change them I size them up with what I have and it is pretty easy to figure out anyway. I got some of the fuel line tubing to try an o-ring delete next time these fail but they keep going strong. I will update this when I eventually try that.


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