The holes aren't tapered either. Roll pins are designed to be used that way. It's what makes 'em cheap to use.
They had torqued it on to last forever. Even heating did not work at first but together with a friend I was able to get it off. Marred the finish of the barrel a bit. So we had to refinish the barrel. I was not all amused. Everything is fine now and will also replace the standard flash hider with the one for the G28 but I hope I will not have to remove a factory installed flash hider any time soon.