The only commercial producer of PBGC I have heard of, is Sages. But they don’t seem to make for .22. So, a tool might be the only way; Pat Marlin makes checkmakers for more or less everything. Or maybe you can find a clever way to make a few, using a .22-something push-through sizer, and a push rod of slightly reduced diameter?
I’ve had a .30-cal PB check maker for a while, and have shot a bit with different loads. My observations so far:
- PBGC added to lubed bullets increase tolerance to about the same level as lubed bullets with regular GC (like 1800 fps ballpark. Results are very similar with PB, PC bullets
- Adding a PBGC with PC on top does not, however, give a drastic increase in tolerance; around +5% powder charge or so, compared to PB/PC.