Murder in the Gunroom by H. Beam Piper

The Lane Fleming collection of early pistols and revolvers was one of the best in the country. When Fleming was found dead on the floor of his locked gunroom, a Confederate-made Colt-type percussion .36 revolver in his hand, the coroner’s verdict was “death by accident.” But Gladys Fleming had her doubts. Enough at any rate to engage Colonel Jefferson Davis Rand—better known just as Jeff—private detective and a pistol-collector himself, to catalogue, appraise, and negotiate the sale of her late husband’s collection.