For handgun storage on a horizontal shelf in a gunsafe, we prefer the vinyl-covered metal handgun racks from Versatile Rack Company. The 4-Gun rack has approximately the same footprint as a single handgun laying flat. These racks have a strong, welded-steel frame, vinyl-coated to protect the finish of your pistols. We've found these work for virtually all size handguns, both semi-autos and revolvers, even when the guns are placed in Bore-Store bags. In fact the fit is just about perfect if you first place a handgun in a Bore-Store bag, which provides about 1/4" of padding all around the gun. Most guns fit best upside-down, but large, scoped handguns can be placed in the rack with the scope on top.
Versatile offers two models, for either 4 guns or 6 guns. These can be purchased directly from Versatile starting at $29.99. But other vendors such as Midway USA, sell them for less. MidwayUSA currently charges $19.99 for the 4-gun version (item 953075), and $24.99 for the 6-gun rack (item 275638). Click HERE for a 360-degree view of the 4-gun unit. There is also an optional stacking unit, shown below. The stacking system retails for $17.00.