I have been loading it for 223 for about four years now. It works more reliably for me in that I get better groups with it than Varget and I load year round and shoot year round. I actually think that as the temp gets a little cooler, down below freezing, my groups seem to tighten up with it. I live and hunt in the Upper Peninsula of Michigan so we have four seasons - early winter, winter, late winter, and construction. Seriously, we have all temperature and humidity extremes and I have yet to notice any difference in either chronographed velocity or accuracy. Plus it meters well for me.