Re: MagnetoSpeed Chronograph Review
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: StanwoodSpartan</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gstaylorg</div><div class="ubbcode-body">I'll answer that Stanwood: if the attached device changes group spread in both horizontal and vertical, you might use it to develop what you think is the "tightest" load, particularly if you're doing OCW testing during load development, only to find the "optimal" load wasn't so great unless you had the unit attached.</div></div>
I see that point, but then I have to ask why you'd run the chrono on it while shooting for groups, load testing or not. I know everyone has their own proceduralo way of load testing, but wouldn't it make the most sense to shoot for groups, pick the best one or two targets, and then run the chrono to see the speed of that load? That way you wouldn't have to worry about the POI change... </div></div>
Actually, for me it would <span style="text-decoration: underline">not</span> make the most sense, because I prefer to get <span style="text-decoration: underline">all</span> the load-related information at the same time and with minimal expenditure. Also, (after the load is finalized) I like clocking the rounds during my routine practice because it doesn't cost me anything extra and improves my velocity estimates nicely (
Confidence Interval ). Your method would preclude that.
The load development options are:
- Work out the load first without knowing the velocities, select the right load, then break out the chrono and shoot 10-15 rounds over it to get the velocity data; whenever you need to verify the velocity - resign to the fact that you can't use those rounds for anything else like accuracy practice.
- Collect velocity data in the process of load development, when the right load is determined - shoot more rounds for velocity data <span style="text-decoration: underline">and</span> accuracy practice, as the chrono is there anyway. And when practice afterwards - strap it on and keep collecting the data for free.
Needless to say I strongly favor the (b) option, and that's where MagnetoSpeed would really shine if it turns out that it doesn't affect grouping badly. POI shift is unpleasant - but since (besides being unavoidable) it's very easy to accommodate for, it is not an issue.
If you follow the approach (a), I think the advantages of MagnetoSpeed would be marginal: you would break out the "big" chrono only when you are ready to clock the load, and keep it stowed out of the way otherwise. So being able to quickly and easily put it on the rifle matters less because in this case you can't use those shots for anything (accuracy, etc) but clocking the velocity. How often do you clock your ammo? Would it make such a big difference if you had to break out Oehler for those probably infrequent events?
I see the biggest advantage of MagnetoSpeed in the ability to just clamp it on - no disturbance for me or for the other range users - and accumulate data while I keep shooting, getting the "benefits of numbers" (because then every extra bullet sent to the target across the chrono improves my velocity data bounds and at the same time serves its primary purpose). <span style="text-decoration: line-through">But if I have to "dedicate" those shots to "clocking" only - my statistical data will be both poorer in quality and more expensive to obtain (because now some of my "shooting budget" is removed from accuracy practice and placed into "clocking").</span>
<span style="font-style: italic"><span style="font-weight: bold">Update.</span>As long as the change to both the POI and group spread is predictable and consistent (and that is likely to depend, among other factors, on how consistent the user is in attaching the device at the same place with the same tension), everything said about the option (b) in load development and data collection afterwards will apply. The only question is - whether the groups will be effected in a consistent way (as opposed to some shrinking down and some spreading up based on the given load).
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Rather long rant, but the issue seems straightforward. It is beneficial if you can clock the rounds while doing something else useful with them. It is not a-must, but it is better both mathematically and financially.