Several of the "inline" designs have bolt and striker assemblies that close over the primed breech face of the barrel - the Remington is unique in that they reamed a deeper primer pocket and made it work with a primed case instead of fumbling with loose primers. There's a solid partition between the "chamber" and the rear of the barrel, with only a flash hole drilled through so the primer flame can reach the powder charge.
Thanks for the information. I think I’ll stick with the old .30-06, though.