The membership numbers of the National Rifle Association are dropping like ducks in a shooting gallery, prompting the gun lobby to offer some incentives to lure recruits.

But one of the incentives, a gun insurance policy, has some longtime members steaming. The NRA pitch through the mail boasts that just by being a paying member of the NRA, a person automatically is entitled to up to $1,000 in coverage against loss or damage to his or her guns.

What the pitch fails to say is that the NRA insurance doesn't pay first if the gun is covered by any other insurance, including a homeowner's or renter's policy.

The insurance offer has put some devout NRA members in a bind. They don't want to speak out against the NRA, which doesn't need any more critics, but they also don't like the idea of being deceived by their beloved organization.

However, Bob Hunter, president of the National Insurance Consumers Organization, said any insurance pitch should disclose any "major condition under which they wouldn't pay out on claims." Hunter said the NRA's failure to note up front that the insurance was secondary is "egregious."

The NRA's membership promotions this year used the usual alarm tactics, such as telling prospective members that the "gun-hating politicians, the anti-gun press and growing opposition groups have launched an all-out effort to take away your guns."

That patented battle cry is accompanied by the notice that the NRA gun insurance coverage has been increased from $600 to $1,000 as an incentive for those who renew their membership. "Surely this great insurance offer and your firearms freedom are worth a lot more than $25 a year {the membership fee}," the mailer says.

Evidently not, because NRA membership is dropping. Extreme political stances, including advocating the repeal of the machine gun ban, have taken their toll, and the NRA is turning off some American gun owners.

We obtained the working papers from the NRA's September 1990 membership meeting. From January to July, the NRA bombarded the nation's mailboxes with 51.3 million pieces of mail -- 19.5 million of them promoting membership and 9 million promoting the insurance policy. Despite the postal blitz, the NRA lost 125,000 old members during the same stretch. The number of new members signing up has dipped by 18 percent this year, or about 300,000. The total NRA membership is 2.6 million.

While the NRA offended some of the faithful with its hard-sell insurance pitch, no one has accused the NRA of breaking the law. The Consumer Protection Act in the District of Columbia, where the NRA is based, says a sales pitch is an "unlawful trade practice" if it misleads a customer by failing to state a "material fact."

The disclaimer at the bottom of the NRA's mailer says that the insurance is subject to conditions spelled out in the master policy on file at NRA headquarters.

We asked the NRA how its sales pitch stood up in light of the Consumer Protection Act. An NRA spokesman refused to comment.