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Old 9th May 2015, 06:24 PM
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RobF RobF is online now
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Join Date: Mar 2010
Member of: Southampton Buccaneers, Parkstone, South Dorset
Location: Poole, Dorset
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Did some ad hoc testing with the springer today, but it wasn't really conclusive enough to publish anything.

With the springer it's hard to get the groups you need to get through 2 sets of sensors, and aim off for wind and group on a specific point to see drop... in the end we settled with a chrono reading at the muzzle to see if it correlated with any high/low shots (it didn't) and down range to just get a handle on what it was doing roughly at the target. So I wasn't concentrating on getting it spot on, just through the sensors. With a PCP it would be easier because you could strap it down.

Also, we think we saw some light shift on the chrono as the sun and clouds came and went. We weren't using our little chronos so this one relied on daylight rather than infra red.

But anyway, it looks like with an average MV of 800 and a terminal velocity average of 600, we're running around 0.023-24 with 7.9 JSB exact express... sizing didn't seem to make much difference, but it seemed to make the MV drop, but not the terminal.. and they seemed more accurate in the HW97. This suggests a small improvement in BC, which despite the MV being lower and the terminal being the same concurs with the slight POI change up we see when sizing on this rig.

So it's all a bit "this seems to be doing this" so we're going to do some more work to at least drive out some of the possible errors.

At least though we look like we're in the right ball park.
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