Not long ago, adjusting an airgun’s performance required a lot of time, gear, and experience. Shooters would often have to completely dismantle their airguns to access key components like the valve ports, transfer ports, and hammer springs. And regulators were reserved only for the elite tuners or high-end airguns. Well, things have certainly changed. With airguns like the Air Venturi Avenger, Reximex, and Zelos, to name a few, budget-minded airgunners can “dial in” the desired performance with a simple twist of a knob or screw. At least, that’s how they are all described. But is it really that simple, or is there more to it?
Here at Airgun Depot, we want you to get the most out of your airgun. It’s why we love these new affordable, adjustable airgun models. In this article, we’ll help you with the other side of the process and that’s how to measure and track your airgun performance so that as you make adjustments, they accomplish your goals. Let’s get started.
Measure Twice, Cut Once
While the idea of “measure twice, cut once” is usually associated with carpentry and manufacturing, the principle applies to tuning and setting up an airgun. But how do you measure performance, and how do you track the results?
The first piece of equipment you’ll need is a chronograph. We suggest getting a chronograph that corresponds with a phone app so that you can easily track your results without needing pen and paper. We offer several great options on our website, starting with the very affordable Pro Chrono Digital DLX and climbing to the radar-based FX Outdoors True Ballistics Chronograph. A chronograph reports the muzzle velocity of the pellet or slug you are shooting. As you make changes to your airgun, you’ll reference the change in muzzle velocity to determine the success or failure of your adjustments.
Get Your Baseline
Before you start making any changes, you’ll want to get a good baseline from your airgun. You’ll want to shoot several full shot strings with multiple pellets. We recommend shooting at a target during these tests to track the group size of the string and see if any vertical changes may correspond to changes in velocity throughout the string. Once you’ve compiled your baseline shot strings and targets across multiple pellets, you are ready to start tracking your airgun’s performance.
Finding the Balance
The most common adjustment people make to their airguns is to try and maximize the power output. While “bigger number better” can be a thing, it’s not always the best option. The laws of physics limit everything in your airgun. Everything else being equal, if you increase one attribute, say power output, then you’ll see a decrease in another part, say shot count. The only way to improve both sides is to find more efficiency somewhere else in the system. You can’t make something from nothing to get “more.” Fortunately, because you have a good baseline, you’ll be able to compare before and after results easily.
We airgunners want the most shots, with the most power while maintaining the best accuracy. Is that too much to ask? Achieving those goals is both time-consuming and also a lot of fun if that’s your thing. Let’s look at a typical “balancing” session using the Air Venturi Avenger Bullpup II.
Sample Optimization Process
The gun typically ships with all the settings turned up to max, which means the regulator is set to 2900PSI, and the hammer spring is maxed out. Once you’ve gathered your baseline data and found the best pellet or slug for your intended use, it’s time to start the process.
Always refer to the manual before tuning your airgun. For the Avenger line of airguns, you’ll need to degass the rifle and turn the reg all the way down. There are clear instructions in the manual for each step. With the gun empty and the reg set to the lowest setting, refill the gun to 300 bar. Now, make a note of your reg pressure. It will be a lot lower than 2900 psi. With regards to your hammer spring setting, we recommend setting it to ½ tension. This gives you leeway to increase or decrease the hammer spring for small adjustments after you’ve set the regulator to your optimal pressure. You should have between five and six turns available on the hammer spring adjuster. Once you’ve determined the maximum range, go ahead and split the difference.
Now, using your desired projectile, shoot a full string from 300 bar down until you’ve equalized your main air pressure and the base regulator pressure. You will probably have many more shots, but shoot at a much lower velocity.
The next step will be to increase the reg pressure by turning the regulator adjustment screw; refer to the manual again as needed. We recommend increasing the pressure by 100PSI at a time and then rerunning the full shot string test.
If you record your shot cards and capture your shot data properly, you can analyze your results after each test to determine whether you are on the right track. Repeat the process until you’ve reached your desired accuracy, velocity, and shot count.
Final Thoughts
We know that’s a lot of data to digest in a short article. Hopefully, this article can help you get moving in the right direction and keep track of your airgun performance. If you need help, please don’t hesitate to give us a call.
