Congressional Republicans today made good on a threat to hold hearings on President Clinton's assault weapons ban by parading eight citizens -- including a grandmother -- before a House subcommittee to extol the need to own firearms for self-defense. "I woke up as the assailants broke in and I calmly walked to our closet where the firearm was stored," Sharon-Jo Ramboz of Walkersville, Md., testified. "I grabbed my Colt AR-15 semiautomatic rifle, [then] pulled back the bolt. That distinctive sound was all I needed to protect four innocent lives and send multiple perpetrators scurrying." An outraged Rep. Charles Schumer (D-N.Y.), who championed the legislation last year, called today's hearing "a smoke screen for the (National Rifle Association)" and an "extremist pro-gun agenda in congressional disguise."