.308? Larger? Those websites DO have large calibers available; you’ve just got to keep checking. Delivery time is the problem, after order confirmation. My *large* shipment of .50cal Beowulf .335gr HPs took 6mos way back in 2011, since it’s proprietary. Yet, I got another *large* shipment of 7.62x51/.308 in 3 weeks, just last Oct.
.270 and larger. .270 is on my short list.