RCBS ChargeMaster Supreme Insert

This insert works similarly to the old straw mod, except without the risk of pushing it too far inside the tube.

The ChargeMaster tube is threaded, which moves the powder forward, but that threading causes extruded powder like Varget to clump easily, which results in overcharges and generally uneven flow rates. This makes the end of the tube smooth, mitigating this issue.

There's a ChargeMaster insert on Thingiverse but it didn't fit my ChargeMaster Supreme so I had to make my own. Unlike the Thingiverse one, this one does not reduce the tube size by as much.

There's also a commercial one available for like $15 (not including tax and ship) but this was like 5 minutes to design and costs like 2 cents to print.

To fit my ChargeMaster, the outer diameter of the insert had to be 0.320".