in case you have a hard time finding the metal pipe for the original Barrel Reducing tool.
then here is a 22mm OD version.
also I made it so it can be clamped down with hose clamps.
besides that fallow the ECM v3 instructions on how to use it.
for those who like the use of rubber bands then here is a printable rubber band holder for the boring rod
and 2 models of measuring caps have been added so you can tape the part that you don't want to be reduced during the OD reducing process. why using the cap over just measuring it out? the idea is that it helps with making a straight marking for the threats. in case the front of the barrel is not perfectly straight making it hard to use callipers on it
The author marked this model as their own original creation. Imported from Thingiverse.