If you can bob the bullet with finger pressure you don't have the .003" of case grip. Ether the case grip has squeezed the bullet smaller or the case has lost all it elasticity and was stretch out during bullet seating. Or your measurements are off, fine measurements are tricky to get accurately.
How to get the trapped air out? Pin through the wad colum trick. Bronze brush case interior to make air escape scratches in the brass. Powder and or wad colum adequately pre-compressed.