On 01/26/2023. My 7mm airgun has been sitting in the case for about a month. The weather had finally cleared up enough to go out to the range again. I made a plan to collect some solid long range data. I prepared 4moa targets that would be placed at 200m (219yds), 300m (329yds), 385m (421yds), and 500m (547yds). This session would be cold bore 5 shots at each target. No warm up or sighter shots. Straight from the case, blow off one blast of air to reset the reg and start shooting for score. The ultimate goal would be to go 20/20. I'd probably be happy to be on target half the time for 10/20. The range was still muddy, and my van would not make it up the hills. I got my van stuck but managed to rock it enough to backup down the slippery mud. Subsequent trip to the far targets involved more walking/hiking. It was a good day and I ended up with some solid data to use for tweaking my dope.
The 7mm, highly modified Benjamin Armada:
Down range view. The neighboring Delta Long Range goes out to 1450 yards, a little too ambitious for airguns in my opinion. Our high power silhouette range has standard berms out to 500m.
I used a Kestrel Drop weather station and Calypso wind meter. I tried to account for all parameters that might affect the extreme long range shots. Including weather and geography (azimuth, latitude, temperature, humidity, barometric pressure, etc). I adjusted my holdoff as the wind changed. I tried to wait for gusts to die down, but after this session, I realized it's better to just use an average reading, as the winds gusting 100's of yards down range are different than what I'm seeing at the bench. The projectile rises about 50 feet above the line of sight on the way to the 500m target. Calypso wind meter on adjustable tripod.
First 5 shots were at 200m. 3 of 5 hits in the 4moa circle:
Next 5 shots were at 300m. 4 of 5 hits in the 4moa circle:
Next 5 shots were at 385m. 4 of 5 hits in the 4moa circle. One shot almost drifted off the cardboard:
Next 5 shots were at 500m. 3 of 5 hits in the 4moa circle. One shot drifted off the cardboard. I needed 107moa of compensation over my zero for this 500m target. I've got 50moa built into the scope mounts, but 107moa is more than I can click for. I dialed in 82moa which is near max, and turned the magnification down some so I could use another 25moa of additional holdover:
I was satisfied with hitting 14 out of 20 for the session. After shooting for score, I shot 5 shots at 35yd to verify my zero and velocity. Velocity was averaging about 1005fps, while my dope was set for 993fps. That might account for the tendency of the shots to be hitting high on average. Also, the G1 drag model is not a perfect match for my boat tail projectile. It's close. I used a straight G1 0.26 BC as a baseline for this session. I'll use the acquired data to do a multiple BC profile in Strelok. That will hopefully get a couple more shots in the circle next time. After that, it's about getting better wind hold offs.
The 7mm, highly modified Benjamin Armada:
Down range view. The neighboring Delta Long Range goes out to 1450 yards, a little too ambitious for airguns in my opinion. Our high power silhouette range has standard berms out to 500m.
I used a Kestrel Drop weather station and Calypso wind meter. I tried to account for all parameters that might affect the extreme long range shots. Including weather and geography (azimuth, latitude, temperature, humidity, barometric pressure, etc). I adjusted my holdoff as the wind changed. I tried to wait for gusts to die down, but after this session, I realized it's better to just use an average reading, as the winds gusting 100's of yards down range are different than what I'm seeing at the bench. The projectile rises about 50 feet above the line of sight on the way to the 500m target. Calypso wind meter on adjustable tripod.
First 5 shots were at 200m. 3 of 5 hits in the 4moa circle:
Next 5 shots were at 300m. 4 of 5 hits in the 4moa circle:
Next 5 shots were at 385m. 4 of 5 hits in the 4moa circle. One shot almost drifted off the cardboard:
Next 5 shots were at 500m. 3 of 5 hits in the 4moa circle. One shot drifted off the cardboard. I needed 107moa of compensation over my zero for this 500m target. I've got 50moa built into the scope mounts, but 107moa is more than I can click for. I dialed in 82moa which is near max, and turned the magnification down some so I could use another 25moa of additional holdover:
I was satisfied with hitting 14 out of 20 for the session. After shooting for score, I shot 5 shots at 35yd to verify my zero and velocity. Velocity was averaging about 1005fps, while my dope was set for 993fps. That might account for the tendency of the shots to be hitting high on average. Also, the G1 drag model is not a perfect match for my boat tail projectile. It's close. I used a straight G1 0.26 BC as a baseline for this session. I'll use the acquired data to do a multiple BC profile in Strelok. That will hopefully get a couple more shots in the circle next time. After that, it's about getting better wind hold offs.
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