I know it’s not a side gate loader, but my Henry .357 Big Boy has digested every .38 Special I’ve ever thrown at it; from 110 gr TCFP to 200 gr LRN. It won’t, however run .38 Special wadcutters, or anything shorter than .38 Special reliably. Since Henry has started adding side gates to their 30-30 and 38-55, maybe it won’t be long until they add them to their pistol caliber carbines.