Longer engagement time? Enough to matter?
Bob
After all four participants had run the course the individual times were averaged together to form a better idea of how the average person’s
night vision would be affected. The following chart represents those average times in a bar graph format. The vertical axis represents time, the horizontal axis breaks out the times between the type of barrel, and the colors represent the lighting conditions.
As shown in the graph, there is a definite difference in the engagement time between the types of
revolvers.
Despite the muzzle flash of the non-ported and side-ported
handguns being roughly equivalent, there is a noticeable increase in the time it takes to run the course in the dark over running it in the light with the side-ported gun—more of a difference than with the non-ported
firearm. This suggests that the position of the muzzle flash may affect the shooter’s night vision.
The discrepancy in times is even larger with the top-ported barrel. However, as the pictures indicated, the top port did not actually produce a fireball in the shooter’s line of sight. Instead, the top-ported revolver produced a muzzle flash similar in size and location to the non-ported revolver—except much brighter. This suggests that a brighter flash—regardless of position—degrades the shooter’s
night visionmore than any change in position.
TTAG Test: Do Ported Handgun Barrels Blind Night Shooters? - The Truth About Guns