Chronograph weirdness at IPSC Nationals

[pivoproseem]

I shot IPSC Nationals in SC Sat with the production "super squad" and observed some chrono issues and several major shooters barely making power, or in Phil Strader and Matt Mink's case, scores being tossed by going sub-minor. Ben Stoeger, using factory ammo, just barely made power..and Tori Nonaka had an issue, too...among others. Two CED chronos with infrared screens in a large cardboard covered box, sitting in direct sunlight were used. One of the shooters on the squad had ammo shot earlier in the day and made power by a comfortable margin. When tested later in the day, it took the 7th shot of the same ammo to BARELY make power. The chronograph was tested again after the issues, and it was considered correct by match officials.

I suspect that heat build up in the box affecting electronics had something to do with variation, since I can't come up with any better explanation. Matt tested his ammo this morning, in much colder conditions, and it made 130pf.... like the week before at IDPA Nationals.

What are some of the variables that could cause a chrono with this set up to read low?????

We shot the chrono stage in the afternoon. My ammo made power, but I had cranked in 2/10th of a grain more Solo 1000 just for insurance. The ammo already made 130pf at home before the increase in charge...made 128pf there. The powder Matt is using is not of the inverse sensitivity type, unlike what I am using.

Edited October 4, 2010 by pivoproseem

[sperman]

Matt tested his ammo this morning, in much colder conditions, and it made 130pf.... like the week before at IDPA Nationals.

What are some of the variables that could cause a chrono with this set up to read low?????

Some powders, like WST, chrono faster in cold conditions. I doubt all of the competitors affected were shooting reverse temperature sensitive powders, but it could be one of the factors involved.

[lneel]

Mine and my son's loads chrono'd within 3 percent of what I get on my dual CED M2 setup that is in an all blacked out box back at home.

Lee

[Aircooled6racer]

Hello: I have often wondered about the electronics and how they react to heat. Last year at the USPSA nationals the pickup sensors were in a black box. Outside the temps were 90 degrees but inside the box it had to be over 120 degrees. I don't think the electronic sensors would like high heat at least I know they don't on race car engines. Silhouette powder is also reverse sensitive. Thanks, Eric

[LChico]

Two CED chronos with infrared screens in a large cardboard covered box, sitting in direct sunlight were used. What are some of the variables that could cause a chrono with this set up to read low?????

Just a few points to clarify:

The chrono box was made of half inch plywood, on 4 sides. The narrow openings (front and back) were heavy cardboard, so that it could be easily replaced. The rest of the box was NOT covered in cardboard & was left the natural wood color. The inside of the entire box was painted black. This box was custom created for this match to meet the specifications of our chronographer (Ken Skeeters). The chrono box that is owned by the range was set up for 2 Oehler Chronographs and Ken wanted to use the CED chronos. He had just used this similar set-up in Las Vegas at the Multigun Nationals without any problems (where it was much hotter).

The weather in South Carolina was great. It was not as hot as it typically is during the State matches in April. We know hot in the southeast (like they know hot the southwest) & it was not hot. Of the 109 shooters in the match, 2 shooters went minor (who had declared major) and two Production shooters went sub minor.

Squad 5 went to chrono between 2 & 2:30 PM. There were 8 Production shooters on that squad. 6 "passed" chrono & two went sub-minor. 2 full squads (21 shooters) followed them at chrono - later in the afternoon - without any problems & 5 of those 21 were Production shooters. If the chrono was recording values greater than 10 points lower than the actual power factor, I would have anticipated much higher numbers of failures at chrono.

Linda Chico

2010 US IPSC Nationals Statistician

Edited October 4, 2010 by LChico

[tunakilla]

We shot the entire match on Friday and our ammo was within 1% of what we read at home. 4 competitors out of 109 total seems to be on the low end of what i have seen over many years.

LChico, GREAT Match as usual

[Joe4d]

I havent shot it in awhile but last time I chronoed WWB 115's it came in at 1080, sub minor, supposedly Remington value pack is even slower but I have never chronoed it.

4 out of 109 ? I saw that many on a single squad once, 3 admitted they had never chronoed the loads, My ammo was right on what it gets at home and a couple majors.

[pivoproseem]

....it seemed our squad had more trouble than would be statistically reasonable with Strader and Mink going sub-minor, Ben just skating by with his factory stuff that makes power everywhere else, and Randi Rogers barely making major, with the same ammo+ gun Sevigny was using, who didn't have any trouble.

..like the chronograph went temporarily insane, just for our squad. I have no experience using infrared screens...so that is why I asked the question. I chronograph a lot and usually my results match within 1 pf at matches, but not this one. It was an awesome match and really enjoyed getting to see the top dogs shoot! Linda and crew also did a super quick job getting the score posted. I just wish me and "mike" weren't such good friends.....

[G-ManBart]

No two chronos will be exactly the same (note the differences between #1 and #2 at any major match), so that means it's unlikely your home chrono is the same as the one at the match. Right there you can lose or gain several PF pretty easily. Then there are powders that get slower when hotter, some that get faster as it gets hotter, and some that don't change significantly either way. Throw in that many folks use mixed and used brass, and that ups the variation you're going to see. Throw in that some folks don't really chrono enough rounds, on enough different days, to really, truly know what their load is doing, and the simple fact that even good, consistent loads still have some variation. Now we're set up for failure at a big match.

If you're not running 135+PF at home, you're risking going sub-Minor at a big match, and that won't be much fun. If you declare Major, and go Minor, the worst that happens is you give up something like 50-100 match points, but you're still shooting for score. R,

[Ben Stoeger]

I will preface this by saying that I know NOTHING about chronos. I have never used one.. ever.

I will just say what happened on my squad.

I shoot Atlanta Arms 147 grain factory stuff... I have for years. I have never gone sub minor.. ever.I was within a whisker of having that happen at the IPSC nationals.

Both Matt Mink and Phil Strader (on my sqaud) DID go sub minor. That is strange... because both of them seem to know what they are doing at least half of the time.

I was told by them that they protested the chrono.. the chrono was checked.. and found to be in working order.

I don't know what happened... but it was strange.

I am not slamming the match (one of the best I have EVER shot).. I enjoyed it a lot... just reporting to people what happened.

Feel free to speculate now among yourselves.

[SNSCaster2]

I'm sure that the guys running the chrono knew what they were doing being a national event, but is it possible the the ammo was handled at all differently? I know I've had ammo that sat in the sun for a little while before being tested and went sub-major..after protest and a chrono re-shoot the ammo out of my bag was tested and made 170ish pf. It didn't take long for WST to get warm and drop pf, and i'm sure other inversely sensitive powders dont take long to warm up either. I'm not sayin.. i'm just sayin...

[ahtsay]

My loads are at around 176-177 pf, precisely in order to avoid "low" reading chronos in different matches. That's just too bad for Matt and Phil.

[jeffsoward]

I don't know exactly what Phil loads, but I can't imagine that he'd change anything without some major testing before a match like this. Does seem kind of odd and random.

I haven't shot any major matches, so how does the protest work? do they voice a protest and, after equipment verification immediately get re-checked? or are they given the option to re-check at another time, say 30min to an hour later?

[dansy]

Fill a protest form give them $100.00 then the process start, all in the IPSC rule book.....since this was a IPSC match.

[Lee King]

I had the exact opposite experience fwiw. Using my cron I came in at 169pf. At IPSC Nats I was 172.

[mda]

I haven't shot any major matches, so how does the protest work? do they voice a protest and, after equipment verification immediately get re-checked? or are they given the option to re-check at another time, say 30min to an hour later?

Chrono is just like any other stage and same rules apply, You only get one chance to shoot it there is not second change if the shooter messes up.

Personally knowing the RM at this match, as well as, his account of it, the Rules were followed by the book. He has a "lot" of calibration and chrono ammo he has used over a few years and matches and checks before and after resulted in 1% difference. Results were also consistent with historical data.

MDA

[pivoproseem]

I'm sure the rules were followed...I just wanted to know what things might have an effect on chronograph consistency with infrared screens.

I still contend there was something wonky with the chronograph stage when our squad went through...too many of the FREAKIN' TOP SHOOTERS IN THE WORLD having problems to be normal.

I haven't shot any major matches, so how does the protest work? do they voice a protest and, after equipment verification immediately get re-checked? or are they given the option to re-check at another time, say 30min to an hour later?

Chrono is just like any other stage and same rules apply, You only get one chance to shoot it there is not second change if the shooter messes up.

Personally knowing the RM at this match, as well as, his account of it, the Rules were followed by the book. He has a "lot" of calibration and chrono ammo he has used over a few years and matches and checks before and after resulted in 1% difference. Results were also consistent with historical data.

MDA

[Strick]

I'm sure the rules were followed...I just wanted to know what things might have an effect on chronograph consistency with infrared screens.

I still contend there was something wonky with the chronograph stage when our squad went through...too many of the FREAKIN' TOP SHOOTERS IN THE WORLD having problems to be normal.

So if it didn't involve the "top shooters in the world" it would have been normal or acceptable? I am not sure why the assumption is that those shooters are infallible and the equipment was in error.

***the above is in no way a statement about those shooters just a general observation***

Edited October 7, 2010 by Strick

[Bob DuBois]

I shot IPSC Nationals in SC Sat with the production "super squad" and observed some chrono issues and several major shooters barely making power, or in Phil Strader and Matt Mink's case, scores being tossed by going sub-minor. Ben Stoeger, using factory ammo, just barely made power..and Tori Nonaka had an issue, too...among others. Two CED chronos with infrared screens in a large cardboard covered box, sitting in direct sunlight were used. One of the shooters on the squad had ammo shot earlier in the day and made power by a comfortable margin. When tested later in the day, it took the 7th shot of the same ammo to BARELY make power. The chronograph was tested again after the issues, and it was considered correct by match officials.

I suspect that heat build up in the box affecting electronics had something to do with variation, since I can't come up with any better explanation. Matt tested his ammo this morning, in much colder conditions, and it made 130pf.... like the week before at IDPA Nationals.

What are some of the variables that could cause a chrono with this set up to read low?????

We shot the chrono stage in the afternoon. My ammo made power, but I had cranked in 2/10th of a grain more Solo 1000 just for insurance. The ammo already made 130pf at home before the increase in charge...made 128pf there. The powder Matt is using is not of the inverse sensitivity type, unlike what I am using.

Did a test with Solo 1000 a month back 96 degree day. Set six rounds on the tail gate of my PU while setting up the chronograph. Shot six rounds that were in the shade out of a box in my bag. PF 130. Shot the six that had been in the sun for just a few min. 124PF. Solo 1000 didn't like being in the heat for just a little while.

[Lee King]

I'm sure the rules were followed...I just wanted to know what things might have an effect on chronograph consistency with infrared screens.

I still contend there was something wonky with the chronograph stage when our squad went through...too many of the FREAKIN' TOP SHOOTERS IN THE WORLD having problems to be normal.

So if it didn't involve the "top shooters in the world" it would not have been normal or acceptable? I am not sure why the assumption is that those shooters are infallible and the equipment was in error.

***the above is in no way a statement about those shooters just a general observation***

Also, it sounds like they are using ammo from AA. Did they check it before? Is it possible AA sent light ammo? Bad batch? Is this ammo custom loaded from AA or is it their off the shelf stuff?

As said previously, nothing against those shooters in particular. But I would be more inclined to question the crono results if they has said something like "I croned my ammo before and made XX pf. Then at the match I went sub-minor". But I have only heard "used this ammo for years and never had a problem before".

Personally I check my ammo before every major just to be sure nothing weird happened with my press. I have had a nut back out on the powder measure causing inconsistent throws. I ran about 200 rounds before I caught it.

[Chills1994]

slight thread drift ahead....and a disclaimer...

I have a CED chronograph with the infrared screens.

a few weeks back I chrono'ed my 9mm minor loads.

I thought I was a good ten to twelve feet back from the first screen, like the instruction manual says. I would fire a shot and I was getting what I thought were spurios readings after the 3rd shot. I usually try for a good 10 shot chrono'ing session. then I would get to the 6th or 7th shot and the screen would start flashing which really means I was getting wonky results.

so after about 30 rounds of that rigamorale, I dumped a few shots into the back berm just off to the side of the chrono.

it was picking up the muzzle blast or the "ejecta"

arrgghh!!!

so I moved it back another 3 to 5 feet, "zero'ed" out the memory and shoot a good all 10 rounds over the chrono.

so my question is this: is there a tape measure attached to the first sky screen of the match chrono that is then run back to the bench or shooting line where the chronographer shoots from???

this would show all the shooters that the chrono is set up in accordance with the owner's manual

[Lee King]

slight thread drift ahead....and a disclaimer...

I have a CED chronograph with the infrared screens.

a few weeks back I chrono'ed my 9mm minor loads.

I thought I was a good ten to twelve feet back from the first screen, like the instruction manual says. I would fire a shot and I was getting what I thought were spurios readings after the 3rd shot. I usually try for a good 10 shot chrono'ing session. then I would get to the 6th or 7th shot and the screen would start flashing which really means I was getting wonky results.

so after about 30 rounds of that rigamorale, I dumped a few shots into the back berm just off to the side of the chrono.

it was picking up the muzzle blast or the "ejecta"

arrgghh!!!

so I moved it back another 3 to 5 feet, "zero'ed" out the memory and shoot a good all 10 rounds over the chrono.

so my question is this: is there a tape measure attached to the first sky screen of the match chrono that is then run back to the bench or shooting line where the chronographer shoots from???

this would show all the shooters that the chrono is set up in accordance with the owner's manual

I didn't see them measure the distance (nor did I see them set it up). But they did have a heavy piece of cardboard with a small hole to shoot through to mitigate the muzzle blast.

Box construction was mentioned earlier in the thread.

[dansy]

Usually a box construction give much better result....then again..

[yuthh]

I shot the IPSC production match in Thailand back in 2006.They used the same type of chrono we are talking about.More than 30% of the shooters who chono in the morning with some rain ,cloud and very humid went sub-minor.Most of them use the ammo from local manufacturer that sponsor the match and claimed their bullets make Minor.Those who went sub-minor were recalled for a random chono in the afternoon(sunshine and no rain).Most of them made Minor.Finally they called off the chrono stage.

Edited October 7, 2010 by yuthh

[paul788]

As I helped Ken setup Friday morning I will chime in. We measured the distance from the front of the rest he uses to shoot from to the front screen. Eleven feet. The two chronographs read within 3-6 fps of each other for the three squads that I watched on Friday. The bags of ammo were kept in the shade on Friday.

I have no knowledge of what occurred Saturday so I won't comment on that.

Paul