BARREL DROOP
by B.B. Pelletier
www.pyramydair.com/blog/2006/01/barrel-droop
Barrel droop is a phrase that was coined by Tim McMurray to describe the air gun barrel that points downward in relation to the top of the receiver (where the scope is mounted). It’s been around as long as there have been air guns, but it was the scope sight that made it visible.
WHAT IS BARREL DROOP?
From the name, you might suspect that we’re talking about a barrel that somehow bends downward, but that’s not the case. Barrel droop is actually a straight barrel that’s been mounted in the receiver so that its axis points downward. There are bent barrels that point down, of course, but that’s not what we mean by barrel droop.
HERE’S WHAT’S HAPPENING
1. First, the bore of your rifle does not run straight through the center of the barrel unless you paid a lot of money for it to be made that way.
2. Second, all screw threads have room for fitting – called “tolerances.” They cannot be perfectly machined and still go together, so if your barrel is screwed into your receiver, it isn’t straight. If it is pressed in, as are most air gun barrels, it isn’t straight either because the hole in the receiver isn’t straight, which is my next point.
3. Third, the hole in a rifle receiver is not bored straight in relation to anything. What would it be straight in relation with?
4. Fourth, the grooves or mounting points on top of the rifle receiver are not straight with the receiver, except by accident. In short, in the world of manufacturing, everything is off by just a little. Usually, the amount they are off is so small that you don’t notice it; and it’s cancelled when you sight in.
THE FACT IS THAT MOST OF TODAY’S SPRING-PISTON AIR RIFLES POINT DOWN TO SOME EXTENT. If the angle is small, you can correct it with the scope adjustments. If it’s large, you need an adjustable scope mount.
Briha
