The reason it makes the firearm produce a V shaped flame is, because of the ports. Since the gases have a chance to escape through those ports and the powder is still burning gas escapes through there, but so do the flames or flash from the burning powder. It also affects velocity.
"It's a gun you loaded on Sunday, and shot all week."
"If God didn't create man equal then Sam Colt had made them equal."
"Fast is fine, but accuracy is everything."