Sen. John McCain, R-Ariz., is surrounded by reporters at the Capitol in Washington, July 15, 2013. (J. Scott Applewhite/AP)

Advocates of removing the dollar bill from circulation in favor of the one-dollar coin are renewing their push for what they say could save the government billions of dollars.

"It's very hard doing the Lord's work here in this city of Satan," Sen. John McCain, R-Ariz., told attendees of a Monday event organized by dollar-coin supporters.

"Our military is being hit so hard by sequester," McCain said, "and it seems to me this is one common-sense remedy. Even in this town 5.5 or 13 billion dollars isn't chump change," he said, referring to estimates by the Government Accountability Office and others of the potential savings over 10 to 30 years.

McCain introduced the COINS Act in June along with Democratic Sens. Mark Udall of Colorado and Tom Harkin of Iowa and Republican Sens. Mike Enzi of Wyoming and Tom Coburn of Oklahoma. The legislation would phase-out one-dollar bills over four years.

The five-term senator said he hopes supporters will at least be able to vote on an amendment to another bill as a way to advocate the change.

Sen. John McCain, R-Ariz., is surrounded by reporters at the Capitol in Washington, July 15, 2013. (J. Scott Applewhite/AP)

McCain warmly greeted his "beloved friend," former Rep. Jim Kolbe, R-Ariz., the honorary co-chairman of the Dollar Coin Alliance. "We campaigned together just after the Spanish-American War," he joked, before congratulating Kolbe on his recent marriage to Hector Alfonso.

Kolbe acknowledged that previous bids to push dollar coins into circulation have been unsuccessful. "You have to phase out the paper dollar to make the coins successful," he said. "Once you do it, they love it. You can't separate Canadians from their Loonies."

Former Treasury Department official Aaron Klein presented a white paper advocating the dollar coin, which noted that Federal Reserve branches found one-dollar bills wear out within 1.8 and 4.8 years, compared to the 30-year lifespan of dollar coins.

"Canada experienced about 10 times their estimated savings," he said. GAO reports in 2011, 2012 and 2013 all tallied savings from the switch, but varied in calculations. Klein's white paper pegs potential savings at around $13.8 billion over 30 years.

Advocates also noted that dollar bills cannot be recycled and that visually impaired people can more easily use coins.

"The government makes money by making money," Kolbe added, noting that the comparative durability of the coins would allow the government to earn more money by "selling" the currency.

John Mitchell, deputy director of the U.S. Mint from 1995 to 2000, told the audience that a one-dollar coin weighs approximately as much as 3 quarters, making it comparatively light.

According to government figures collected in December 2012, which Mitchell had on-hand, more than 1.4 billion one-dollar coins are being held in Federal Reserve depots. The mint held around 51 million of the coins itself.

In June 2011 there were $1.2 billion of the dollars laying in Federal Reserve vaults, NPR reported. The surplus attracted widespread scorn and the mint has since lowered dollar-coin production.

"There are billions of quarters and billions of pennies sitting around too," said William Christian of Citizens Against Government Waste, a group supporting the changeover.

Kolbe said the surplus of dollar coins is actually a good thing for his cause.

"That's some significant advantage," he said. "We have an inventory."

The former Arizona congressman, who left office in 2003, said opponents of yanking dollar bills include ink and paper companies, "some other groups like the Mount Vernon Society because George Washington is on the dollar," and the Federal Reserve because it reflects profits from paper dollars on its books.

At least one representative of the coin-metal industry, which stands to gain at the expense of paper and ink companies, was in the audience Monday.

"We can be sentimental about a lot of things, but a piece of paper that's ragged around the edges I can't get sentimental about," Kolbe said.