I remember reading somewhere he about how someone opened up gas checks so they could seat them on powder coated bullets but after looking I cannot fine that post. Can someone please remind me what you are using. These are 30 cal for 300 BO bullets.

I do that for some of my molds. NOE molds in particular I've always had trouble seating gas checks without shaving lead or powder coating. Some other molds need it and some don't.

I use a short steel rod with a bevel turned on one end as a hand held flaring tool, but also have some made up as top punches. The idea is for the "meplat" of the tool to be right at normal gas check ID, so that pushing it down flares the check.

Can post pics later if you want.

Scott, just fyi, I have quit using GC on 30-30 with PC bullets with no leading. I bake them nose down on a plate with holes to hold upright

Thanks guys.

If that 300 Blk is an AR15, and you're using full power (not subsonic) loads, you'll want to keep using gas checks.
For low pressure subsonic loads you can leave the gas checks off.

If it's not a gas operated rifle, you may be able to skip the gas checks for all loads.