Thread: Chronographs, what's the story

Yesterday I shot some new powder for groups, chrony readings reasonably steady, I mean not to much variation, sorted out a couple of loads that looked interesting and took them back today for a recheck.
Same load , same sort of grouping but readings near 100FPS faster the readings were as reasonably steady as yesterday.

Had the sun shields on both days, sun not out as much yesterday, but still there, but bright today,
then clould cover came over and the speed dropped 50-80-fps for the same grn weight.

Drives me nuts, anybody got a solution.

Validate at distance is the only solution I got, it's a real piss off as it happens to me every time I go out and not willing to spend big bucks on a flash chrony...

Your right, thats the only true way, but it just drives me fuken nuts cause it happens time and time again, you think you have it sorted, then bugger the damn things are supposedly going faster.

Glad I'm not the only one that doubts the chronograph ha ha

Now you know why I got an Oehler

You still need to validate at distances but at least I know the speeds are about right.

Shame about the $$$ not worth it unless you are doing heaps.

These sonic things, anyone have an opinion about them yet?

I only trust it when it's sunny. The numbers from clear, bright sunlight seem to line up at long range.

What brands are you guys using? I use a Competition Electronics one, it seems to be more reliable than my friends shooting chrony (the Canadian made ones). The numbers seem to stack up at distance, and it's never thrown a hissy fit on me.

F1 shooting chrony

Shooting F1

it's been shot, hit with fragments from an exploding suppressor, and still works

it just needs bright light to be accurate

i have got an oelher and a pro chrono which reads to with in 4fps of the oelher so mainly use the prochrono and then verify by shooting

should look at getting a magnetospeed v2 chrony dude . or getting a bunch of mates together and putting in for one , accurate as , so easy and fast to set up and not affected by light. well worth the cash rather than struggling through life on the conventional chronys wondering wtf is going on and then end up shooting it haha

Jakewire I know bugger all about this stuff but a question occurs to me and that is "could the difference in speed be explained by the difference in temperature of the powder in the rounds on the two days"? A test would be to take ten rounds from the same load, put five in the fridge over night and leave five out. On the next day run the five from the fridge through the chrony from straight out of the fridge ( or chilly bin if you have to transport to the range - i.e. no time to come up to the ambient temperature) and then put the other five through the chrony. If there is a dramatic difference in the fps readings between the two groups then the powder burn is likely to be sensitive to its temperature at ignition and will possibly explain the difference in speed on any two given days.

Just a lay mans hypothesis.

I only use my f1 comparatively.
Ie shoot a known load that has been over Gregs ohler and validated at range and if its say fast 80fps subtract that from the load in question.
Gets pretty close.

The Magnetto speed ones are great, but shooting groups with it on can be a lottery esp with a light weight sporter barrel.