I've only quite recently jumped into casting for rifle calibers. I have done a good bit of .300 BLK, and just started playing with some .308 win. My primary question, is, is there any significant benefit in accuracy to traditional lubing and gas checking over powder coating? Obviously this question is directed towards GC designed molds. Or should I just order a PB mold with no lube grooves and powder coat away. Right now I am interested in casting for the .308, 30-06, and likely .303 and 7.7 JAP in the near future. If the gas checks are preferable, where do you typically buy them. I know some of you guys make them as well as use some small vendors. I appreciate your input.