Attorneys for America's oldest gun maker say gun owners' suspicions about the government may explain why only a relative handful have expressed interest in getting their Remington rifles repaired under a nationwide class action settlement. Nonetheless, they say claims have jumped roughly 25 percent since February, and that is reason enough for a federal appeals court to let the settlement proceed.

Timing is critical, with this year's hunting season just a few months away.

The case involves Remington's iconic Model 700 rifle, as well as a dozen other Remington firearms with similar designs. CNBC first reported in 2010 on allegations that, for decades, Remington covered up a design flaw that allows the guns to fire without the trigger being pulled.

Lawsuits have linked the alleged defect to dozens of deaths and hundreds of serious injuries. Remington has steadfastly denied the allegations. The company maintains that the guns are safe and free of defects, and blames all of the incidents on user errors.

Nonetheless, the company has agreed to replace the trigger mechanisms in nearly all of the guns, free of charge, in hopes of putting the matter behind itself once and for all. Earlier this year, a federal judge in Kansas City approved the class action settlement, which covers roughly 7.5 million guns.

But two Model 700 owners — a sheriff's deputy in Louisiana and an attorney in Oklahoma — appealed the ruling to the 8th U.S. Circuit Court of Appeals. Lewis Frost and Richard Denney accuse Remington of deliberately downplaying the risk from the guns in order to suppress claims under the settlement. They argue that the small number of claims — only about 22,000 as of February — proves the company has not done enough to notify the public.

Attorneys general from 13 states and the District of Columbia have also urged the appeals court to reject the settlement, calling the guns a threat to public safety.

If the owners of all 7.5 million guns were to submit claims, the repairs would cost Remington upwards of half a billion dollars, according to multiple court filings. As of last week, according to Remington and plaintiffs' attorneys, the number of claims had risen to 29,214. While that still represents less than half of one percent of the guns in question, Remington argues in its latest filing that the figure is significant.

"Low claims rates are hardly unusual in consumer class actions," the filing says, adding that the issue is especially tricky when it comes to guns.

"Rifle owners may be suspicious of any claims process that involves the government and lawyers," the filing says.

Attorneys for class action plaintiffs — who stand to collect $12.5 million in fees if the appeal is denied — agree that the settlement is fair, and that the public has received ample notice.

"Both the agreement and claims process have been extensively publicized through the formal due process notice plan, supplemental notice plan, and independent media," they write.

It is not clear how long it will take before the appeals court rules on the settlement. Regardless, it is unlikely that customers who send in their guns will get them back in time for this fall's hunting season.

The official web site for the settlement estimates the repair process will take 12 weeks from the time Remington receives the gun, and all claims are currently on hold as the appeal process plays out.

In addition, some owners will be unable to get their guns retrofitted at all. Under the settlement, owners of some of the oldest models are only eligible to receive a Remington product voucher worth as little as $10.

In addition to the Model 700, the settlement covers Remington models Seven, Sportsman 78, 673, 710, 715, 770, 600, 660, 721, 722, 725, and the XP-100 pistol.