So you made the plunge. You threw down some serious cash for a BB gun. You excitedly fill the rifle and take your first shot with premium European pellets.
Much to your disappointment, it isn’t grouping well. You consider smashing your rifle against a wall.
Hold on, Scooter. We’ve just started our amazing airgun adventure.
Here’s a quick how to for setting up your rifle. Be sure to read the disclaimer at the end. Happily, you don’t need a chronograph for his method.
Fill the rifle 2800-3000 psi. Back the power adjuster all the way down. Shoot a 3 shot group and increase the power by 1 on the gun or 16 notches on the wheel itself. Repeat.
You may have to stare for a while, but 4:5 and 5:1 seemed to shoot best in this example.
Refill the rifle and have a shoot off to confirm he accuracy:
Still about equal… so I had a shoot off at longer range:
Now we have a definite winner.
Typically, the results will be much easier to see than this, which is why I wanted to show this specific example. I’ll show you something that was tough and how I crapped victory, so hopefully you’ll have an easier time finding the solution and crapping your very own victory.
Tuning without a Chronograph
Accuracy is key. Who cares how fast the pellet is flying if it’s shooting well? To tune, I recommend using an accurate setup and shoot at long range (50-100 yards). It will be easier to see what the pellet is doing the further the distance. Shoot on a calm day. Wind is one less factor to deal with.
You want to see a consistent point of impact. (Please read “what is a pressure curve”).
Note your starting pressure. Typically, it It’ll begin by shooting low. This is caused by the high pressure inside the cylinder stopping the valve from opening properly resulting in a slower speed.
Shoot until there is a consistent point of impact. The POI should shift upwards until it stops rising. Note the pressure reading on the gun.
Shoot until point of impact drops. Stop shooting, note the pressure, and refill the rifle to the point where consistent points of impact were given.
Repeat until you always have consistent points of impact and know the exact fill pressure. I use 2550 psi and power wheel 4(gun):5(wheel). Much lower pressure than I would have thought. It gives a low shot count, but the shots are guaranteed to be consistent.
This method works like a charm, and will show you exact results, unlike a chronograph. But to truly understand your rifle and what the pellet is doing, you need a chronograph. It provides much more depth to tuning… and it takes less pellets.