Nonsense. You can unequivocally say that gun control would reduce (not eliminate, but drastically reduce) the risk of mass shootings and gun homicides in general, because it's been proven time and time again.
How many mass shootings have you had in Britain since stricter gun control measures were instituted after Hungerford and Dunblane? How many in Australia since stricter gun control measures were put in place following Port Arthur? How many in Germany? Canada? Japan? The US has probably had more mass shootings since the start of 2016 than all of those countries combined have had since the start of the 21st century.
With the exception of Japan, which has a long history of public disarmament by local and state rulers dating back centuries to the time of the Shoguns (and increased during the demilitarization after WWII) and the strictest gun (and sword!) control measures of any democracy (only hunting rifles, shotguns, and air guns are allowed, and still strictly licensed), those other countries all had similar hunting, sporting, and gun collecting traditions to the US and still have plenty of legal gun owners, though not nearly as many as the US does. They're just much more heavily licensed and background checked, regulated, and restricted by type of firearm.
Japan had a total of 22 gun homicides in the entire country in 2007 and it was considered a
national disgrace that prompted long term soul searching and further legislation proposals because it was a dramatic increase from the previous year's two gun homicides (it had dropped to 11 by 2008, but was still considered cause for alarm). You could get those numbers during a
particularly bad week in Chicago.
Despite paranoid ravings from Wayne LaPierre and the NRA designed to frighten the dwindling number of gun owners into buying and stockpiling more weapons (the number of gun owners is way down but the number of guns owned remains high), no one here is proposing anything on the order of Japan's severe gun control measures. No one's "coming for your guns" or saying you (general you) can't hunt or target shoot or defend your home. All they want are reasonable restrictions like better background checks, longer waiting periods, greater regulation on types of firearms you can own and magazine capacity, etc. Measures which have been demonstrably effective in other countries.