A revolver sits on display in the Sturm, Ruger & Co., Inc. booth on the exhibition floor of the 144th National Rifle Association (NRA) Annual Meetings and Exhibits.

A group of nuns and other faith-based investors won a shareholder vote at Sturm Ruger & Co. requiring one of the nation's largest gun-makers to prepare a report about the risks of its business.

Ruger's CEO, Christopher Killoy, said at the company's annual meeting on Wednesday that the company will comply and prepare the report. "Shareholders have spoken," he said.

But, he added, the winning proposal "cannot force us to change our business," and "cannot change what Ruger is about and what we stand for."

It was the first major test this year for faith-based shareholder groups, which have been urging the nation's gun industry to act after recent extreme examples of gun violence.

These shareholder groups have reached out to big banks and investment firms for their support, an effort that has paid off in this instance. BlackRock, the world's largest asset manager and Sturm Ruger's largest shareholder because of its giant index fund business, voted its 2.8 million shares in favor of the shareholder proposal, a source told CNBC.

Vanguard is the second-largest shareholder, though its vote is unknown. A spokesman wasn't immediately available.