Before the Scamdemic: 222, 22-250, 243, 270, 7mm RM, 30-30, 303, 308, 30-06
After the Scamdemic: 222, 223, 22-250, 243, 270, 7mmRM, 308, 30-06.
In the USA add 357.
The Big 3: 30-06, 308, 7mm RM.
The Gheymore might crack the Top 10, certainly not Top 5. A local store has it, but wait, it's Aguila FMJ.
The 30-06 has by far the most loads available with the 308 in a distant 2nd. That said, I've seen Gas Stations where 30-30 or 7mm RM was the only centerfire ammo.
Strange stuff shows up, I've bought 7.5x55 and Bismuth Shotshells at Gas Stations and 6.5 Japanese in Northerm BC.