A double action revolver’s trigger pull does not get lighter with subsequent pulls. Each pull is identical, having to move the cylinder the same diameter to the next chamber, and having to pull the hammer the same distance back. The action relies purely on the shooter delivering mechanical leverage via the trigger to operate.

Double Action/Single Action Autoloaders may have been what you were thinking of, as they start with a longer, heavier pull, then the slide cocks the hammer on each shot, resulting in lighter subsequent shots. This is what you referred to in the newer semi-auto pistols section. This is common on newer military issue handguns such as the Beretta 92/M9 and Sig Sauer handguns.

However, many new pistols use a modified double action system (like GLOCK, S&W, Springfield Armory, and many of H&K and Sig’s Double Action Only systems) that produce an identical trigger pull with each shot, some being under 4 pounds (such as the Glock series 3.5-pound trigger connector, which is a common aftermarket addition, and a stock feature on their long slide competition models).