Posted April 27, 2015 9:55 pm by Comments

By James Rummel

bullet spin

Yet more reader questions are answered. This time around, it concerns yet again my past post on derringers.

I heard that derringers will usually keyhole. Is that bad?”

Is keyholing bad? Yeah, pretty much. But to understand why we must first discuss what is meant by keyholing.

The way to make bullets stable in flight is to give them a spin. If they are revolving around their long axis while flying downrange, they will be much more accurate.

This spin is imparted to the bullet by the rifling cut inside of the barrel. But what happens if the barrel is so short that the bullet pops out before it has time to start to spin around the long axis? If that happens, the bullet most usually starts to tumble around any old way.

This significantly reduces the range and accuracy of the shot. The bullet tends to drift around wherever it likes, wandering about like a dog sniffing trees. Not only that, but it also tends to strike the target in some way other than nose first.

KeyHole-Tear-1

KeyHole-Tear-2

(Picture source.)

Those might not look …read more

Via:: Hell In a Handbasket

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