I don't reload, and despite being able to convert guns between calibers, due to the cost I just don't (except for .40S&W / 357SIG). The comparison of the barrel cost compared to the cost of a whole new gun being just a bit more usually draws (suckers) me in. So for that reason, I would choose a G20. Having said that, you do reload, so the G21 may be a better option for your needs. In the end, you are going to have fun! Both will serve you well!