High brass shells are shotgun shells that have a brass base (or head) that extends up the body by about 3/4" or so. Low brass hulls extend up the body by 1/8-1/4" or so. In paper hulls (now rarely seen) high brass is used for reliability of extraction. High brass was used in the early plastic hulls to prevent splitting and burn thru; it is mostly no longer needed due to improved plastics. In modern shot shells, the only real difference between high brass and low brass hulls is a marketing difference. Powerfull factory loads use high brass hulls, while standard or target loads use the low brass hulls. There is no correlation between the mechanical strength of the hull and amount of brass in the base.
