by Tom Gaylord
Writing as B.B. Pelletier
The Air Venturi Seneca Aspen precharged pneumatic air rifle.
This report covers:
- Not the accuracy test
- Man plans…
- Testing as a PCP
- Mounting the scope
- Back to 10 meters
- Back to 25 yards
- Scope adjustments
- My test plan
- First group of five
- Shots 6 through 10
- Second group
- Third group
Get ready to learn something, kids, because school is in session!
Not the accuracy test
Today would normally be the start of the accuracy test for a normal PCP air rifle, but the Air Venturi Seneca Aspen PCP is anything but normal! I did shoot a lot of targets today, but there aren’t going to be any dimes in the pictures. I was just trying to figure this rifle out!
I figured I would mount the 4X32 AO scope that comes bundled with the rifle and at least start to shoot for accuracy. Well, there is a saying about thoughts like that. Man plans and God laughs! If you don’t believe it, read the book of Ecclesiastes. It was written by King Solomon, who was the wisest man ever to have lived. Near the end of his life he figured out the meaning of life and boiled it down to just that. Oh, he didn’t say it that way — he was more reverent and polite about it, but in chapter 12, verses 12 through 14, he pretty much sums it up that way.
Testing as a PCP
Although the Aspen is a PCP, I have never tested it that way. It also has a built-in air pump and when I tested the .22 I always pumped it, because I learned it liked much lower air pressures than the reservoir was built to contain. So, I thought, why not just pump it and I can be the regulator? It worked like a charm, if you can recall those tests.
But we learned in Part 2 while testing the velocity of this .25 that it likes much higher pressures. So, this was the perfect time, I thought, to fill the rifle from a tank and use it as a PCP. My plan was to sight in and then shoot some groups at 25 yards to discover the best pellets and also whether high or low power was best. And, that was when the laughter started!
I connected the fill probe to the rifle and filled to 3600 psi/250 bar. Let me warn you — the reservoir fills very fast. Go easy on the air tank knob until you learn the rifle or you will have to bleed it down. It may be capable of shooting at higher pressures, but it may not want to. In fact — it doesn’t.
Mounting the scope
The next step after filling was to mount the scope. As long as the rifle comes with a scope, I at least need to try it. The two-piece rings have two-screw caps so there is no trick to tightening them. I did shim under the rear of the scope with one thickness of credit card simply because 75 percent of the air rifles and firearms I have ever scoped need some kind of downward slant. If you put a shim in and they don’t need it you do no harm — you just get a little more elevation adjustment. If you need it and don’t have it you have to remount the scope.
I mounted the 4X32 AO scope that comes with the Aspen in the rings that are also bundled.
I decided to use the single shot tray today. That allows me to switch pellets at will, although the need for that never arose because this is where things got strange. All testing today was done with the Benjamin dome. I always start by sighting in at 10-12 feet from the target. That eliminates any surprises later on.
I began shooting on low power. The thought was I would then switch to high power when all the pellets had been tested on low, but the laughter started to increase. You’ll see why in a bit.
The first shot (shot 1) hit below the target paper, but at 12 feet you expect it to be low. In fact, it would be at least as far below the aimpoint as the center of the bore is below the sight plane (the center of the objective lens). My first shot was just a little below that and a little to the right. Thank goodness for the shim!
Back to 10 meters
A second shot (shot 2) hit very close by, so I raised the scope several clicks and also dialed in some left adjustment. The third shot (shot 3) hit a little higher and over to the left. It wasn’t quite centered but was close. Close enough that I backed up to 10 meters and fired again. This shot (shot 4) was higher but still not high enough. It was also over to the right again, so I increased the elevation and dialed in a lot of left adjustment. The final shot at 10 meters (shot 5) was at the bottom of the target, but too far to the left. I then adjusted the scope way up and way back to the right. At this point I felt comfortable to move back to 25 yards.
Back to 25 yards
When you move from 10 meters to 25 yards your impact point will rise without adjusting the scope 95 percent of the time. At least mine does. It rises by an inch, so I factor for that when sighting-in.
The first shot from 25 yards (shot 6) hit just outside the black at 1:30 position. Now I was at 25 yards, so the adjustment clicks move the impact more. Each click is 1/4-inch at 100 yards, so 4 clicks are 1/4-inch at 25 yards. I dropped 4 clicks and went left 4 clicks, which should have put the impact into the upper right quadrant of the black, but instead, shots 7 and 8 were very close to the center of the bull. In retrospect I should have fired another shot, but these two were stacked so I felt I could begin shooting a group. Ha!
Here is the sight-in target described in the text above.
I will mention here than the scope adjustments seemed to move the impact point of the pellet exactly as they should. There was no stiction of the reticle remaining in any place after it was adjusted.
My test plan
I thought I would shoot pellets until the rifle started dropping them below the aimpoint, which opens the group. Of course I will do this on both power settings with all pellets, so there is a lot of shooting to be done. I will take a picture of the group after every 5 shots.
Let’s see, I’m shooting on low power and I have already shot 8 shots on the fill. The tank still reads about 2900 psi, which should be good enough for some more shooting, so I continued, hoping I was right about the pressure.
After sight-in that was 8 shots the Aspen’s pressure gauge looked like this. I read it as 2900 psi.
First group of five
And I watched the first shot curve through the scope and land almost two inches to the left and above the center of the bullseye! Okay, I’m here to learn about the rifle. Let’s keep shooting.
Shot number two hits to the left of the first shot. See? I was right! The shots are walking to the left and towards what I thought was the aimpoint. Shot three hits a little to the left of shot two and now there is a line of three holes that is walking down and to the left — towards the center of the bull. Oh, what a smart boy am I!
I marked shots 1 through 3 in this group of 5, so you could see how they walked toward what I thought was the established impact point. Shots 4 and 5 didn’t bear that out.
Okay, so maybe I wasn’t right about where the point of impact was after all. Or maybe the rifle wants the pressure to go even lower? So back to the bench I went and continued shooting at this same target. Surely this time the shots will walk into the center of the bull.
Shots 6 through 10
This time I just shot and didn’t pay any attention to where the pellets were hitting. Unfortunately I could see all of them through the 4-power scope, which is my way of telling you that, besides the adjustments working well, this little scope is also pretty clear. But, darn it, the shots just weren’t going where they were supposed to!
There are the five new holes and I don’t know what to tell you about them, except they aren’t where they are supposed to be! I saw none of them in flight.