By Shawn Zeller, CQ Staff

Neither the Brady Campaign to Prevent Gun Violence nor the National Rifle Association would ever refer to the other as a centrist lobby in the gun control debate.

But both groups are awkwardly straddling the center after joining forces on legislation to restrict people with mental illness from buying guns. The bill, which Congress cleared before Christmas, grew out of last spring’s deadly shootings at Virginia Tech University. Gun advocates to the right of the NRA assailed the group for backing the bill, since in their view it didn’t give would-be gun owners with a history of mental illness enough of a chance to protest their ineligibility to buy guns, or to get the finding reversed. And now the Brady Campaign is getting hit from its left by gun control supporters who say the final language permits too wide a berth for spurned gun buyers to protest their placement on the list barring them from gun purchases.

“The bill is now nothing more than a gun lobby wish list,” says Kristen Rand, legislative director of the Violence Policy Center. Other gun control advocates have echoed the center’s complaints.

The real target of their outrage would seem to be longtime legislative supporters such as Sen. Charles E. Schumer and Rep. Carolyn McCarthy , the two New York Democrats who sponsored it, rather than the legislation itself. The bill, which President Bush is expected to sign, authorizes $875 million through fiscal 2013 to support state efforts to keep the watch list more effectively updated.

Rand and her allies say the main culprit in undoing the bill’s original provisions was GOP Sen. Tom Coburn of Oklahoma, who held up the bill after conservative groups helped convince him that it would bar gun ownership to veterans who had sought mental health treatment in Veterans Affairs Department facilities. Gun control advocates say the bill too narrowly defines mental illness in order to deflect veterans out of the database, while also imposing on the VA onerous new protocols for processing protests from veterans. The new language, says Rand, “will waste millions of taxpayer dollars restoring the gun privileges of persons previously determined to present a danger to themselves or others.”

McCarthy, though, says the bill was a model of bipartisan cooperation, and Peter Hamm, spokesman for the Brady Campaign, says his estranged allies took too hard a line from the start. “They wanted perfect and wouldn’t settle for the good from day one,” he says. “Anything that had any kind of procedures for people getting gun rights restored was not going to fly with them. We politely but completely disagreed with them.”