Country1, the end velocity and energy are what get reported. So the energy lost from a revolver doesn't mean anything.

What matters is barrel length, bullet weight, and powder used to propel the bullet.

It's those factors that make magnums with less than 3" barrels require loads that burn their powder faster than standard loads to have similar velocity and energy with their longer barreled cousins.

Your non-magnum loads are more forgiving with energy loss in shorter barreled guns. This has been proven true many times over by the professional shooters. It's a matter of matching specific rounds with specific guns to have the best possible effect when the time comes.