Blowpipe laser sight mount

I bought an aluminium pipe with 16mm inner diameter for shooting paper darts. To help me aim i bought a [cheap laser sight from China](https://www.banggood.com/532nm-5mW-Red-Dot-Laser-Sight-Scope-Tactical-Black-with-Adjustable-Rail-Mount-p-1171352.html?p=6E2214592974201405G7) and created a mount in [OpenSCAD](https://www.openscad.org/). Calibrating is easily done by looking through the tube at the desired distance and turning the screws on the laser until you see the red dot in the middle of the