Rifling PVC - Bigger

This is a perfect example of why engineers should never be left to their own devices or unemployed. Following on from the earlier successful attempt at rifling a 1" barrel, I've now prepped a 2" barrel.
This is probably my favorite size as empty caulk tubes are a near perfect fit and fly like lawn darts. So here's the button, fitted with 6 cutters.

The .410 dart is for scale. For this one I added a couple of ball bearings and an axle with which to push/pull/whatever the button through the pipe. Turned out I just put a piece of pipe over the all thread and hammered the thing to the bottom, then did the same the other way to get it out. The bearings let the button turn as the cutters are angled at 7 degrees. It worked.

Getting decent pictures is tough but you can see the 6 grooves 1/16" wide running down the pipe. Test darts were one "Nerf" dart made from pipe insulation, and one caulk tube with one wrap of decorative felt to give a tight fit into the barrel.

Results on this one were inconclusive. I may need to cut the grooves again to get them a bit deeper. Or something. Probably also need to make a cutter with a more aggressive twist although large bores like this seemingly don't need as much.