Hi there (over a year later!) I came across your post while doing a search on CS9 magazines.This I am certain of per Fastbolt (highly skilled and informational individual on here) there is zero you can do with that factory mag release without having to buy another.To remove it it has to be drilled out and another pin and button have to be installed-stupid IMO.BUT there is a guy on here that removed the stock one and did a little machining for the mag release to accept the removeable kind where you push the little tab on the side and unscrew the button and he did an outstanding job.If I find the post I will pass it on to you.