by Tom Gaylord
Writing as B.B. Pelletier
This report covers:
- Before we begin — the inside diameter of the gas tube
- The test
- First shot
- Shot away!
- Move target to 11 meters
- Shot two
- Shot three from 10 meters
- Back up to 17 meters
- Adjusted the rear sight one last time
- Shots 5 and 6
- End of the test
- Shots 7 and 8
Today I shoot the Umarex Air Javelin airbow for accuracy. I know that a lot of readers have been waiting for this! This will be an accuracy test, but as I said before, the AJ is such an important shooter that this report is going to proceed along different lines.
Before we begin — the inside diameter of the gas tube
Oh my, have some readers obsessed over this! They are busy redesigning the AJ the way it should have been, if only Umarex engineers were smart enough to have recognized it! I hear from AirForce all the time that they wish they were as clever as the people who redesign their airguns. But they know they aren’t, so they just let it ride.
The outside diameter of the gas tube measures 0.278-inches. The wall thickness of the tube measures 0.022-inches. That would make the inside diameter 0.234-inches. But when I measured the ID with my calibers I get readings between 0.135 and 0.155-inches. I know that my calipers are not the proper way to measure the ID of this tube, so I will hold up a 0.20/5mm pellet next to the tube and let you take a guess.
That is a Sheridan .20 caliber pellet in the jaws of my Mitutoyo 8-inch dial caliper. The band at the base of the pellet measures exactly 0.2000-inches. The nose of the pellet that is next to the gas tube measures 0.1945-inches.
I will shoot from a sandbag rest — the same as I did when I first shot the AJ at the SHOT Show. There I was 25 yards from the target. But Umarex had sighted the AJ in with a red dot sight and all I had to do that day was shoot it. Today I was on my own.
I started with the target bag 15 feet from the AJ. Yes I am using the back-up iron sights (BUIS), but since they detach from the AJ and I had to install them, I want to be certain of my shot! I taped a 10-meter pistol target to the center of the target bag to give me a more definite aiming point.
I have so many things to tell you about shot number one. First, the AJ is extremely easy to cock! Nobody will have a problem doing it. When the arrow is seated you cock the gun.
I was wearing my new hearing aids, so my description of the discharge sound will now be more precise.
The trigger is two stage with a looooooong first stage pull! The trigger then breaks heavily but cleanly.
I’m using the BUIS and you will remember that I told you that front fiberoptic is large. I decided to use a center-of-mass hold, which means holding the front orange dot in the center of the bull. That turned out to be a mistake, but I didn’t know it yet.
I will say this — the orange fiberoptic front sight gathers light extremely well. The thing glowed like it was battery-powered!
Load the arrow with the gun uncocked and on safe. It slides down the gas tube easily until it contacts the o-rings in the rear. Then it needs an extra push.
The arrow has two red “feathers” and one white one. On all bows the orientation of the odd-colored feather is important, but the manual makes no mention of it anywhere I can see. So I made it a point to load each arrow with the white feather pointing up.
The first shot went off with a loud report and a small cloud of CO2 gas. The arrow hit the target below the bull but in line with its center. Remember, I am holding the fiberoptic dot as close to the center of the bull as I can.
Move target to 11 meters
I moved the target bag out to what I thought was 10 meters. When I measured it from the tip of the arrow it was 11 meters. I adjusted the rear sight up and shot the second shot.
Shot two hit the target about one inch below shot one and a little farther from the centerline of the bull. I had not known how much to adjust the rear sight up, so I didn’t go more than a full turn of the screw. I started hearing the clicks of the detent as I did this.
Shot three from 10 meters
I adjusted the rear sight up a little and fired the next shot. It struck the target to the left of the first two. At 10 meters the fiberoptic front dot is almost as large as the bullseye.
The third shot went to the left a bit. I’m still at 10 meters here, and the front dot is almost as large as the 2.5-inch black bullseye. I measured these three shots after withdrawing the arrows and the measure 1.617-inches apart, center-to-crenter.
Back up to 17 meters
I now moved back to 17 meters, which is almost as far as I can go in my little backyard. At 17 meters the front dot is larger than the bull! It is still smaller than the 8-inch kill zone of a whitetail deer, but I have lost a lot of precision with the target I’m using today. That was what I meant at the beginning of this report when I said I probably picked the wrong sights for today’s test, but now I’m not so sure I did. Because of what I did buyers will have a good idea of how useful the BUIS are and can plan accordingly. I will guess that the BUIS will work to 25 yards on a deer. Beyond that a dot sight will be preferred, but in a hunting scenario you might want the dot for better visibility, anyway.
The first shot went “whump” — a decidedly different sound than the others had made. I could not see the arrow from where I sat so I walked up to the bag. The arrow was way low on the bag. That was why it sounded so different. Apparently the arrow dropped a by three inches when I moved back the 7 meters, so I had some more sight adjustments to make.
Adjusted the rear sight one last time
I cranked the rear sight up as far as it would go and still allow me to hear the clicks. Let’s see.
Shots 5 and 6
The next two shots are from 17 meters with the rear sight cranked up pretty far. The first shot climbed on the target.
End of the test
At this point I realized that it was futile to continue. I had exceeded the fiberoptic sight’s range for accuracy. I was guessing where I was aiming and was off by several inches on every shot. I am almost certain that with a dot sight I can shoot near Robin Hood shots (one arrow inside another) at this close distance, so it is pointless to continue.
The AJ is loud. I call it a 4 on the Pyramyd AIR sound scale. The sound does diminish as the gas bleeds down, but it still cracked on the 8th shot.
Shots 7 and 8
I went back outside when the sun was high in the sky and fired two more shots offhand from 20 meters. This time I was at the limit of my back yard, without shooting on an angle. Offhand I put two more shots into the target bag 1.5 inches apart and one inch below the aim point. This time there was no paper bullseye, so I aimed at the target bag itself, which was much easier. Perhaps we can stretch the range for the BUIS to 20 meters if you aren’t aiming at a small target. A grapefruit would be ideal!
I like the AJ a lot! It is just as much fun to shoot as I’m making it sound. And I think that once I get a red dot sight mounted we are going to see some real accuracy!