Heston spoke Monday to a crowd of about 700 in New Hampshire as part of the NRA's "Vote Freedom First" campaign.
He held a rifle in front of him, then uttered to the roaring crowd his famous line, "From my cold dead hands."
Heston, president of the NRA since 1998, announced in August that he had been diagnosed with Alzheimer's. His speech in Manchester on Monday was one of 12 scheduled campaign stops in key states in the next two weeks.
"It is an honor to me to stand here in front of you all and be received as generously as you have done not only tonight but through the years," Heston said.
On Tuesday, Heston held a similar rally in Joplin, Mo.
The 78-year-old actor is urging his audience to vote for candidates who support Second Amendment rights and to persuade others to vote for those candidates as well.
Many in the audience cried during Heston's speech in New Hampshire.
The actor announced in a taped message in August that his doctors had diagnosed symptoms of the neurological disease, which causes memory loss so severe in advanced cases that people can no longer recognize close friends or loved ones.
His most prominent role recently has been as president of the NRA. His term ends in April 2003.