One of the features on the Air Arms 410, and 510 models of PCP's, that until recently, I have never used, or given much thought to, is the adjustable power capability.
Because most of the shooting that I do is considered "long range" as far as air gun ranges are concerned, I normally run my guns wide open for max power.
However, I now have a hunting situation where I don't need or want max power, so I decided to use the power control on my AA 510 side lever carbine, and turn the power down to around 18 to 20 fpe.
Since I would need to use my chronograph to accomplish this, I figured what the heck, lets take some time and see just what "adjustable power" really means, and find out the range of power the controller would let me choose.
Some other PCP's have adjustable power also. Some have the power control located where you need to remove the gun from the stock to reach the control, and others have the control located on the receiver, where it is easily available.
The AA 410, and 510 series of PCP's, have the power control located on the right side of the receiver, as seen in the picture above.
As seen in the picture below, on the opposite side of the receiver, there is a power scale with five index marks, with + (plus) on the right, and - (minus) on the left, and three in-between. On the end of the power control shaft, is a groove, that's used as a pointer (looks like a screwdriver slot) that shows where the power is currently set at.
It would be nice if there were a detent, click stop, at each of the index marks, but there aren't. The only two settings that are easily repeatable, are + High power, or - Low power. There are stops at both of those settings, everything in-between, is continuously variable.
I decided to shoot a string at each index mark, and see what the power and shot count would be at each of those settings. My pellet of choice is the 16 grain JSB Exact Jumbo. Starting with + HIGH, and working down to - LOW, here are the results of those tests. I could probably drop the ES a bit by playing with the fill pressure some, but for this test it's close enough for govmint work.
HIGH MED HIGH MEDIUM MEDIUM LOW
3000 psi fill 3000 psi fill 3000 psi fill 3000 psi fill
Avg - 922 fps Avg - 874 Avg - 712 Avg - 573
ES - 33 fps ES - 33 fps ES - 33 ES - 36
Shots - 20 Shots - 25 Shots - 30 Shots - 40
Fpe - 30 Fpe - 27 Fpe - 18 Fpe - 12
3000 psi fill
Avg - 481
ES - 18
Shots - 50
Fpe - 8
That's a pretty wide range of power. On the Low setting, 8 fpe isn't a whole lot more than my FWB 300S, and the shot count would keep you going for a while.
Medium low, at 12 fpe, isn't much less than my 20 cal R9, and Medium power, at 18 fpe, is about the same as my .20 cal Theoben Crusader generated when I still owned it.
Medium high, at 27 fpe, is the same as my AA 410SL carbine generates at high power, and High, at 30 fpe is the same as many of my other full size PCP's generate at full power.
Change the pellet weight, and all of these numbers would obviously change, but this gives a good reading on just what "adjustable power" means, when talking about an AA 510 carbine.
I sure wish the in-between settings had click stops. Oh well.
After the above tests, I set the gun up for 18 fpe, shooting the 14.5 grain DYNAMIC PCP-2's, and using the set screw located under the power control knob, locked the control in place, so I don't accidentally move it while hunting.
All in all, I'm very pleased with the performance of this carbine so far, and now I know what the different power settings really bring to the party.
View the full article on the VarmintAir Blog