I first printed everything out of 3D Fuel PLa+ and when I assembled it and I inserted a 3D printed CMMG replica 22 mag, it snapped off the feed ramp at the base of the ramp. OK, so I’ll print the barrel adapter out of Fiberon PA612CF, anneal it for 12 hours, and let it sit out for moisture. Assembled everything today and the bolt wouldn’t fully close at first until I forced it closed. And…the feed ramp split at the base of the ramp again. It looks like the bottom of the metal reinforcement plate is striking the top of the feed ramp, as the Fiberon version now has a dent.
Another odd thing with both, the adapter pin holes for the handguard don’t anlign evenly with the cuts in the RS22 barrel. There is maybe an 1/16” (or less) of the barrel that shows on the feed ramp side of the pin holes. It takes a hammer to get one of the pins through both holes and the barrel cutouts. Additionally, dummy rounds would eject with the PLA+ barrel adapter but not the Fiberon one.
Anyone else experiencing this issue with the Wisp and an RS22 barrel?
Likely an issue with tolerance stacking. With rs22 it’s a bit harder to adjust since the barrel can’t be moved in easily. It would be best if I release bolts with different length options so people can choose the right one that fits.
Eventually I’m going to do a different design (replica this time) with a receiver in a chassis bolt action with a multi piece receiver so headspace can be adjusted easier.
Here are photos of one of the casings that got stuck, though I didn’t think they looked too bad. But there is a little bulge in front of the rim.
I’ve updated the files with alternate length bolts. The guide now also explains one way of measuring headspace since I got asked that a lot.
You’re amazing! I’ve already downloaded v1.1 and will print some of the longer reinforced bolts to see which does the trick.