To an Airgun Friend
I was aked the other day why an airgunner could not shoot his new Gamo and well as his "Old .20 caliber". This is my response.
Those .20 caliber pump air rifles of our youth were the high
point of American air rifles, and they still influence our approach to air
rifles.
Those air rifles shot with a
simple mechanism. A spring and a hammer are retained by a trigger. Release the
trigger and the hammer strikes the firing valve stem, opening the valve, and
air rushes into the barrel, propelling the pellet out the barrel. The power
came from a pump built into the rifle. The pump pressurized the air before the
shot is fired.
A century of shooting these air rifles
left American airguners with a sense that an air rifle was like a scaled down
.22 rim fire. Now that spring/piston
airguns have become popular, that sense has been challenged. With spring
powered guns, like your Gamo, some new shooting techniques are needed for good
results.
Spring/piston airguns have an entirely different firing
cycle. They carry their pump behind the pellet rather than under the barrel.
Well before the shot, a spring is compressed behind a piston. The spring drives
the piston to compress the air after the trigger has been released. There are
no valves, just two seals that only hold pressure for micro seconds. This is an
elegant system, but elegance comes with a price.
The pellet doesn’t leave the barrel before near the end of
the piston’s stroke. The piston can bounce off a rebounding wave of compressed
air near the end of the compression cycle before it is finally stopped by the
end of the cylinder. This sets up forces
that weren’t there in that .20 pump air rifle, and they all happen before the
pellet leaves the barrel
You can shoot that .20 like a .22 rim fire. Hold it firmly
from trigger squeeze to follow through. Steady the rifle on a tree trunk or a
fencepost and it will reward you with a good shot. Shoot a springer that way
and your heart will be broken. Springers aren’t bad. It only means that your
shooting technique has to accommodate the springer’s Newtonian world of action
and reaction.
Isolate the action reaction cycle with your hands. Grasp the
rifle lightly. Let it pulse in your hands during the shot cycle. Don’t rest it
on a hard surface unless your hand is between the gun and that surface.
Generations of airgun hunters and plinkers in Europe have done excellent
shooting with spring piston airguns, and you will too.
Good shooting,
Ron
