I haven't taken the time to research, but I wonder if there is a 20 gauge speed wrench available. I have had one for 15-20 years that I use for 12 comp guns. It inserts into the barrel and a knurled knob on top tightens up a large rubber mandrel in the bore. It locks very tightly and will insert or remove any choke tube I have ever tried it on. I went to it due to having so many different bore sizes on competition guns. It works perfectly and doesn't need a notch to work. If they are made in 20 guage, I plan on buying one when my RBL arrives (hopefully in the next few weeks). It would work much better than any kind of push in friction fit.
