I have been shooting a 20ga CSMC 21 for close to 20 years. It has been flawless and couldn’t be happier with it.

I have an RBL that did have issues firing the second barrel(single trigger), I sent it back to them, to quickly repaired and it has been flawless ever since.

I wouldn’t hesitate ordering a 21 from them exactly as you want one built. I may have them build me a Heavy Duck as my next toy.