Rings won’t fit in grooves on pistons.. HELP!

I’m partway through building the bottom end of my 383. I was just about to gap the piston rings but when I test fit them they won’t go in the grooves on the pistons…

Do I need special rings or something? 30 over TRW L2293 dome pistons and Hastings 30 over moly rings.
0830DA04-5C2F-4EC3-A497-80C848FB0B19.jpeg

4DA766FA-22CF-4C3A-92D5-2DF421D625D2.jpeg