Chrono Certification

[kgunz11]

I would argue that the "kachunk" insures no bridging is occurring inside the powder measure, and helps insure a more consistent charge. My measure has not problems throwing consistent charges, even with the kachunk...

Huge +1

The springs or rubber bands are not necessary for consistent powder drops.

They were for Mark.

Never hurts to have a little extra help. That's why you have a spare extractor now right?

[Singlestack]

I would argue that the "kachunk" insures no bridging is occurring inside the powder measure, and helps insure a more consistent charge. My measure has not problems throwing consistent charges, even with the kachunk...

Huge +1

The springs or rubber bands are not necessary for consistent powder drops.

They were for Mark.

Never hurts to have a little extra help. That's why you have a spare extractor now right?

If he has the Fail-Safe return system, something is not adjusted correctly.

[LPatterson]

This has gotten far, far afield from what the original poster was asking.

But since it has I too use a rubber band to return the powder bar and a piece of scotch tape to keep the UniqueTek micrometer from moving and if it is a flake powder I strap a fish tank aerator to the powder measure reservoir.

[Tom D]

Getting back to the original post, at most major matches, Area and Nationals, CED is the Chrono used. For that reason alone, this is the only one I would buy to test my loads. Are some more accurate? Maybe, I don't know. But it still comes down to using what the mtches are going to use. If you are using a controled lab to test your loads, it wouldn't matter if the one at the match says you are 100 FPS too slow, you are going minor.

I know that when we have Ken Sketers doing Chrono, he tests it at the match with a known load, from his pistol that has been tested at a lot of matches. So at least it is consistant.

Tom

[Skydiver]

I know that when we have Ken Sketers doing Chrono, he tests it at the match with a known load, from his pistol that has been tested at a lot of matches. So at least it is consistant.

Tom

Consistent that he gets the same delta as compared to past tests? And if so, is a fudge factor added to people's velocities when competitors actually run their guns through chrono? Or is adjustment done to the distance between the skyscreens to get a consistent result that is closer to his past values?

For example, if the chrono at the match shows a consistent 100fps slower than the lowest measurement he got with the same gun and load from past matches. Do competitors get a +100fps when their loads are tested? I'm assuming that the answer is "no" because the rules say the digits are read straight off the chrono.

[mactiger]

I know that when we have Ken Sketers doing Chrono, he tests it at the match with a known load, from his pistol that has been tested at a lot of matches. So at least it is consistant.

Tom

Consistent that he gets the same delta as compared to past tests? And if so, is a fudge factor added to people's velocities when competitors actually run their guns through chrono? Or is adjustment done to the distance between the skyscreens to get a consistent result that is closer to his past values?

For example, if the chrono at the match shows a consistent 100fps slower than the lowest measurement he got with the same gun and load from past matches. Do competitors get a +100fps when their loads are tested? I'm assuming that the answer is "no" because the rules say the digits are read straight off the chrono.

Consistent with regard to the chrono guy noticing that his chrono is off if he isn't within a few fps of what he's been getting. And, no, there isn't any fudge factor, but a reliable chrono guy will notify the RM that his chrono is off and they can deal with it as needed.

I know Greg Lent and Ken Skeeters run a very consistent chrono. Not only does Greg test it with his loads and gun, I've run my calibration load over it many times, and it's always between 120 and 122 pf, no matter what the weather.

A chronograph is an instrument: it has to be set up properly and tested properly to produce accurate, reproducible results. Any chrono that uses ambient light is going to vary widely from one that uses a reliable light source in a relatively light-tight box.

Like Tom said, if the match uses CED, you might want to use one to test your ammo, if possible. CED sponsors the Nationals, for sure, and that's what we'll be using.

Troy

[Schutzenmeister]

Once upon a time, Greg used to use an Oehler. At some point he switched to the CED. I asked him why. As I recall he indicated it had nothing to do with one machine or the other being better or mor accurate, just that CED made us an offer too good to pass up.

I have consistently used my Oehler at home - set up in a coffin with artificial light, just as Greg preaches - and I have always had results within a few feet per second of Greg's and Ken's official results at every match I've been at ... reguardless of which chrono they were using or where the match was held.

1 - Pay attention to your loads. As some folks have pointed out, they thought the chrono was in error only to find out their powder measure wasn't dropping charges as they expected.

2 - Pay attention to how the chrono is set up. I tried to get at this earlier when I suggested folks reread some of Greg's articles, but the suggestion was dismissed. Setup of the chrono is CRITICAL if you want consistent results. The biggest single problem (IMO) in chrono setup it LIGHT! (Honest - For real!!! Just as Troy hinted.) The second problem tends to be screen spacing, and the final problem can be those pesky little DIP switches inside. (If they're configured wrong, however, it is frequently IMMEDIATELY obvious!)

[kgunz11]

Why not use a chrono that is indifferent to light and accurate with or without it? Are we so bastardized that we can only use what is given to us? As long as the chrono is set up properly and works properly, all is good. It doesn't really matter to me what name is on it. The thread was started to ask the question of how they were calibrated.

[mactiger]

Why not use a chrono that is indifferent to light and accurate with or without it? Are we so bastardized that we can only use what is given to us? As long as the chrono is set up properly and works properly, all is good. It doesn't really matter to me what name is on it. The thread was started to ask the question of how they were calibrated.

Chronographs are generally calibrated by the manufacturer, and they also generally are loathe to give out the procedure. They are "QC" checked by the operator using a standard load--reproducibility and repeatability are the key items. Light is critical for their operation, therefore a steady, constant light supply, whether it's visible or infrared, is required. Ambient light (sunlight) varies too much, even on a cloudless day (because it strikes the sensors differently from minute to minute), to be reliable. Incandescent bulbs in a closed box, or IR emitters in the case of a CED, are the best choice. IF all variables are the same (constant light, screens set to the recommended distance, dip switches in proper position, and environmental conditions within the manufacturer's specs, the results from one brand to another should be the same, or within tolerance, as Schutzenmeister stated. The most common problems encountered at chrono are bullet weight (usually lighter than stated) and errant powder charges, in other words,error on the part of the ammo manufacturer or his equipment.

Edited May 8, 2010 by mactiger

[Schutzenmeister]

Why not use a chrono that is indifferent to light and accurate with or without it? Are we so bastardized that we can only use what is given to us? As long as the chrono is set up properly and works properly, all is good. It doesn't really matter to me what name is on it. The thread was started to ask the question of how they were calibrated.

K

Honestly ... Not to sound flip ... But if you know of a brand of chrono that uses something OTHER than light (be it visible or IR), could you let me in on it? Seriously, I'm not aware of any, which is not to say one does not exist.

[G-ManBart]

2 - Pay attention to how the chrono is set up. I tried to get at this earlier when I suggested folks reread some of Greg's articles, but the suggestion was dismissed.

Most, if not all, of us participating in this thread have read Greg's articles previously. I'm certain I've read them at least two or three times. They don't offer as much detail as what's being posted here, which is what I said earlier. It's not that it was dismissed, it's just that we've already done it...so you're kind of suggesting we do something we've already done

[Corey]

why is everyone making such a big deal about this as its turned out to be? we either trust the equipment to do its job or we dont? we use 2 of them in case one does go haywire or get s something internally screwed up...seems like a non-issue and something pretty far down the list of things to im gonna worry about at a major event...

[BillD]

why is everyone making such a big deal about this as its turned out to be? we either trust the equipment to do its job or we dont? we use 2 of them in case one does go haywire or get s something internally screwed up...seems like a non-issue and something pretty far down the list of things to im gonna worry about at a major event...

How many major matches have you gone minor at?

I always pucker a little tighter at the chrono stage. Everyone I know does. Guys just want to make sure that the ammo that chrono's just fine at home doesn't make them go minor at a major match.

I went to a 3 gun state championship once and my .223 ammo didn't make minor out of a 16" barreled gun. I didn't even think to check it, it was Georgia Arms ammo.

That means I got NO SCORE for any of the rifle stuff. When you figure in hotel, gas, food, match fees, etc, that was a pretty expensive trip for not even getting a score.

[Corey]

why is everyone making such a big deal about this as its turned out to be? we either trust the equipment to do its job or we dont? we use 2 of them in case one does go haywire or get s something internally screwed up...seems like a non-issue and something pretty far down the list of things to im gonna worry about at a major event...

How many major matches have you gone minor at?

I always pucker a little tighter at the chrono stage. Everyone I know does. Guys just want to make sure that the ammo that chrono's just fine at home doesn't make them go minor at a major match.

I went to a 3 gun state championship once and my .223 ammo didn't make minor out of a 16" barreled gun. I didn't even think to check it, it was Georgia Arms ammo.

That means I got NO SCORE for any of the rifle stuff. When you figure in hotel, gas, food, match fees, etc, that was a pretty expensive trip for not even getting a score.

non yet, hopefully wont, haha. I guess I don't worry too much about it tho. I guess i feel confident in the redundancy of the two chronos and my loads that i wont get whacked and lose a bunch of points (I hit all As anyway so it doesnt matter )

[BillD]

I've just seen a lot of guys go minor when they were sure they had a 170+ PF. It happened to two friends of mine this year at majors.

It is something to be concerned about especially when it costs you 15% in points.