Issue With .22cal Checks, Lip Left On Base

I'll try and get a picture uploaded, but I'm getting a lip on the bottom of my gas checks after seating them onto my Mihec 65gr NATO boolits. This occurs with my Lee .225" and my NOE .225" push through dies. The issue is worse with aluminum checks, but also occurs on copper checks. I believe the issue is the pushrod diameter being too small, at .220". Seems like the check material is forming into that .005" void between sizer die and pushrod. Any other ideas? I've tried sizing first and then running them through again to install the check, I've tried lube, powder coating first, making sure the check is fully seated before running them through. For now I'm stuck sizing base first.

Base first is how I often size. I also use a NOE chamfer tool to trim the base edges so I get a tight seating of the gas check. I also lube with a touch of Lee sizing lube. But I still get some that I hit with a file to deal with a bit of base lip.

I am setting gas checks before powder coating, which is one reason I use the Lee lube, washes off with hot water and once the bullets dry it doesn't give problems with powder coating. I'm using fairly hard lead so I don't notice distortion of the nose from doing base first. And from everything I have read base matters more than nose.

problems with gas checks are why I have been investing in swagging dies, mucho dinero but it gives me better boolits in the smaller or faster calibers.

Rogerdat, I also have that tool, but dont get a lot of flash generally. Do you use the top punch to size base first? I do, it's a challenge to keep everything aligned, and slow going g in general with tiny boolits. Lee will makeke me a custom pushrod for $20. I think it's worth it to test my hypothesis.

"Any other ideas? "

Thinner GC material.

When you are sizing down a projectile, the displaced metal has to go somewhere.
So, if you can get your GC thickness (times 2) plus your boolits GC shank diameter, to be closer to .225 then there will be little to no metal displaced during sizing/crimping and eliminate this issue