The unusual fundraiser, first reported by the Sunlight Foundation, is being hosted by the New Jersey Second Amendment Society, which, according to its website, is "a gun rights advocacy group that lobbies against unreasonable gun control laws." Lonegan is a staunch opponent of new gun control laws.

Attendees pay a registration fee for the event, after which they can choose from a number of rifle and pistol options, as well as varying numbers of rounds, for different donations to the Republican's campaign.

A $125 donation gets the contributor five rounds from the Barrett M107, a semi-automatic sniper rifle that is currently used by the military. Donations range from $15 to shoot a round from the Magnum Research BFR .45-70 revolver to $40 to shoot five rounds from the Savage 10P .308 rifle.

The NJSAS is also offering two "mystery" rifles, for a contribution of $50 each. According to the invite, children 10 and older can participate in the event if accompanied by a parent or guardian.

Lonegan remains the decided underdog in the race to replace deceased Sen. Frank Lautenberg (D-N.J.), and has come under fire this week for calling "weird" comments Democratic opponent Cory Booker made dismissing speculation over his sexuality.

The fundraiser is one of many he'll likely need to help boost his profile, as he started August with just $150,000 cash on hand.