There is just no way that Holly, played by Lois Chiles, could simply have had that revolver hidden under the folds of her nightgown as it lays spread out on the bed. She was seen preparing herself to present an alluring sight to J.R. as he enters the room. She was alone, so there was no need to hide the firearm, yet there was simply no sign of it. Such a revolver is big and heavy and couldn't have been hidden on her person underneath such light bed-clothes. Stuck under the pillow? No. That's clearly not what happened. She pulled that gun from the folds of her nightgown as if by magic. in real life, this basic situation can of course easily be done, just not as seamlessly as on film here, considering just how bulky a firearm and how dainty her clothing is.