I would agree that vintage guns (and their shooters) may not survive modern loadings, but in the case of these Stevens 520/620's, they are made out of a serious block of steel and built heavy as hell.
My son and I trimmed a couple down to 19" and we could not be more pleased with how they shoot and handle. The takedown feature is very sweet. We can pack them into a 20" X 6" X 2" case that looks very unlike what is contained inside. With practice, they go back together and are rockin' in less than 10 seconds.