I saw this in Beverly Hills Cop II!
This was a plot device, some odd casings were found that could not be classified...investigation concluded that they were custom-made handloads, a .308Win case cut down and sized to hold a .44 bullet as ammunition for a .44 AutoMag pistol, ammunition for which was hard to find and/or expensive.
From Wikipedia: "The .44 Auto Mag Pistol (AMP) cartridge was introduced in 1971. Its rimless, straight wall case was originally formed by trimming the .308 Winchester or .30-06 case to 1.30 inches (33 mm)."
This would be the only reason I could think of to cut down a casing from a military caliber that was produced by IVI.