Under Missouri's concealed weapons referendum, guns almost a foot and a half long could be concealed and carried. Permit holders could use any legal handgun, defined as having a barrel length of less than 16 inches, including some semiautomatic weapons.
What Proposition B opponents call cop killer guns such as Uzi pistols, MAC11s and TEC9s could also be carried.
But supporters of the proposition say that's just a scare tactic.
They say the guns most commonly carried won't be large and say in other states with conceal and carry laws people usually prefer guns that are small and light.
"More women than men apply for the permits, and they want something that will fit in their purse," said Brett Feinstein, spokesperson for Missourians Against Crime.
Compact guns, such as the Mini Master, that fold down to just larger than a pocket knife are the smallest guns available and have a barrel length of about one inch. The Thompson Center would be one of the largest weapons with a barrel measuring 15 and a half inches.
"Guns like that are heavy and difficult to conceal without drawing attention to yourself," said Douglas Grindstaff, manager at Target Masters. "The point of concealed weapons is that no one notices them."
Grindstaff doesn't think people will be carrying guns with large barrels. He predicts the most commonly carried concealed weapon will be the something similar to the Taurus .38 caliber revolver, which has about a two inch barrel.
Opponents say the size doesn't matter. "Hidden handguns of any size have the potential to be dangerous," said Lauren Massey, spokesperson for the Safe Schools and Workplaces Committee.
Safe Schools was forced to pull an ad showing that claimed the concealed weapons law would allow residents to carry an Uzi rifle, which is already illegal under federal laws. The ad now shows an Uzi pistol.
While Missourians can't yet carry concealed weapons that doesn't mean they can't pack guns.
Under current laws anyone who can legally own a gun can carry it if the weapon is clearly visible. Some exceptions apply under certain circumstances such as if the person is intoxicated or near a school or polling place.
"Think of the old west, if you wanted to walk down main street with a gun strapped in a holster, it's legal now," said Lt. Chris Ricks, Missouri Highway Patrol spokesman.
The current law has no size restrictions, even rifles could be carried so long as they were not being used to threaten anyone, Ricks said.
Carrying a concealed weapon is now considered a felony crime.