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Electronic devices at the F-Class nationals

I don't recall anyone stating exactly how many rounds they needed to get on a target before it would need to be refaced. At the 4-gun last weekend we started with newly refaced Fclass target faces, shot 176 rounds in the center with just a few 9's and the target was indistinguishable from a newly refaced target when viewed through a scope. Keep in mind that the targets are not being covered with 3/4 inch black pasters on every hole so the white lines stay sharply visible for a long time.
 
I don't recall anyone stating exactly how many rounds they needed to get on a target before it would need to be refaced. At the 4-gun last weekend we started with newly refaced Fclass target faces, shot 176 rounds in the center with just a few 9's and the target was indistinguishable from a newly refaced target when viewed through a scope. Keep in mind that the targets are not being covered with 3/4 inch black pasters on every hole so the white lines stay sharply visible for a long time.
Yeah - I'm curious as to the reasoning for offsetting as the faces do last a long time without the use of the pasters - given the angst it causes some with the offset (arguable a legitimate cause for concern).
 
I applaud Winnequah Gun Club for taking the initiative and applying all the toils to install the e-targets. I eagerly await for Nationals to arrive to use the system. In regards to a statement about the "plug value" on the tablet being larger than what is actually shot. According to the SMT techs that I have conversed, with this is a metric system which converts all values to inches. The hard (factory default) "plug hole value" is a metric conversion of .308. The system uses 7.82mm. "Quote"
- internally, all our measurements are done in mm. So, the 10-ring has a radius of 254mm, and the bullet has a diameter of 7.82mm therefore a radius of 3.91mm
- if the center of the bullet is (254+3.91=257.91mm) or closer to the center of the target, then it is counted as a "10". In inches that is 10.1539" Pretty straightforward in my opinion. They did state if one uses the "full zoom" on their tablet, they will see the actual 7.82mm bullet hole not a larger graphical representation of it. If it touches the line you should receive the score. They even included some javascript of the software calculations for me to analyze. Very impressed with the company. In closing my concern was if in "full zoom" I see a shot touching but don't receive the score....this would be a challenge as it shouldn't happen and 99.99% of the time probably won't. 30 some days and counting! Eric in DL
 
I applaud Winnequah Gun Club for taking the initiative and applying all the toils to install the e-targets. I eagerly await for Nationals to arrive to use the system. In regards to a statement about the "plug value" on the tablet being larger than what is actually shot. According to the SMT techs that I have conversed, with this is a metric system which converts all values to inches. The hard (factory default) "plug hole value" is a metric conversion of .308. The system uses 7.82mm. "Quote"
- internally, all our measurements are done in mm. So, the 10-ring has a radius of 254mm, and the bullet has a diameter of 7.82mm therefore a radius of 3.91mm
- if the center of the bullet is (254+3.91=257.91mm) or closer to the center of the target, then it is counted as a "10". In inches that is 10.1539" Pretty straightforward in my opinion. They did state if one uses the "full zoom" on their tablet, they will see the actual 7.82mm bullet hole not a larger graphical representation of it. If it touches the line you should receive the score. They even included some javascript of the software calculations for me to analyze. Very impressed with the company. In closing my concern was if in "full zoom" I see a shot touching but don't receive the score....this would be a challenge as it shouldn't happen and 99.99% of the time probably won't. 30 some days and counting! Eric in DL


yeah that bit is news - very few would know to zoom in and is it ok to do it after the scoring shots have been fired and then challenge?
 
That is a gray area. Current NRA rule is as soon as you fire the next shot you accept the value of the previous. However with the e-targets you always have the shot locations present. Guessing for this year the answer is no, you shoot the next shot you accept it. However I can see the rule being changed for e-targets.
 
That is a gray area. Current NRA rule is as soon as you fire the next shot you accept the value of the previous. However with the e-targets you always have the shot locations present. Guessing for this year the answer is no, you shoot the next shot you accept it. However I can see the rule being changed for e-targets.

Thanks - interesting - personally I'm keen on leaving the rule as is (i.e. there is no need to change the rule just because there is new capability), but one of those things to evolve over time.
 
Well, while you can have the ET computer calculate (by whatever method) an absolute point of impact, around which you draw a circumference according to the default gauging value (7.82/2 or 3.91mm radius) or maybe actual bullet radius (if the system knows this), there is the problem of measurement error. Or the "Area of Uncertainty" - a well known engineering term.

There are always errors - a better term is arguably uncertainties - in a measurement (not just in ET's) and the problem is that these always accumulate and never contract. Errors are caused by many things. What can be done to accommodate them?

So you might calculate a shot position along with say an error - or area of uncertainty - of say 5mm. Or more. Errors tend to increase as distance traveled increases and not necessarily in a linear fashion. Again, there are many reasons for this.

So if you numerically determine an error of say 5mm, what do you do with it? It is basically saying that the shot position is x,y but it could also be anywhere within 5mm of that point.

So it really means that perhaps you expand the gauge value (3.91mm radius) by 5mm and then look at the picture (assuming the shown shot size is in perspective with the surrounds - like scoring rings)? And then if that new circumference touches the line, do you then say that the shot deserves a higher score or not? Not forgetting though that that extra 5mm in circumference (due to a numerically calculated error) could have brought the shot closer - or just as easily taken it further away - from the scoring line. It is, after all, an "area of uncertainty".

It is possible to show this expanded "shot" size - as the mathematics associated with the shot calculation can determine this error. If this is done, and the expanded circumference touches the ring, should the shooter be given the benefit of the doubt and have any challenge upheld? (A challenge of an electronic target is largely a foreign concept). The error could have also taken the shot further away? The key word here is "uncertainty".

ET's are all about measurement, uncertainty (errors), and eventually numbers. And in the case of acoustic targets especially, physics.

A lot of factors affect the errors associated with a particular shot in an acoustic target - and there are a couple of surprises (based on analysis of quite a few thousand shots over some years here in Australia). It is rare for there to be no errors - in fact, if there is no measurable error in a shot measurement we get a bit suspicious. I can't say that it doesn't matter what causes them if you measure them. What I say is that they do exist in the real world and to ignore them is probably a mistake. In my case (disclaimer below) I use the measured errors of a target to provide an indication of the overall condition of a target rather than an accuracy indicator of an individual shot.

To summarise a bit, I believe that the absolute impact point (centre of bullet) minus the circumference (3.91 mm in the case of the standard 7.82mm gauge) is not really correct given that we know that there are variable measurement errors. But on the other hand, to consider the inherent system errors of an acoustic electronic target and the impact on what they might have on individual shot results may well open a can of worms.

Geoff Roberts
Ozscore Electronic Targets
Australia.
 
In regards to applying an offset (vertical generally) to the results shown on the screen relative to where they actually impact on the target, to preserve the centre scoring rings, well, a few of the customers of my ET - and another brand - tried this. And stopped it.

Why?

Well, in the words of one shooter the mental effort to adjust away from his known zero for a particular range/distance "screwed with his mind".

So now they prefer to simply shoot out the centre of the target and re-centre as required. More often than they'd like (in the case of scope shooters) but apparently that results in fewer headaches.

That was a couple of years ago. I am not sure if anyone has revisited this recently or not. Actually, I thought it was a good idea...

Geoff Roberts.
Ozscore.
Australia.
 
Geoff,
I enjoyed reading your explanation but what do you think the error rate on just your average human puller? I know over time we have all been touched by a missed shot or at least we felt we would have shot better if the service was stepped up.
The nut behind the gun seems to come loose about the second time the line officer calls for faster service on the same target number. I know the human puller doesn't get much faster when he already felt he was providing his best service.
There are issues and chance with both methods.

John
 
We haven't had any issues with our shooters using an offset on our targets. Just something you get use to.

I'm sure your right Shawn and hats off to all your work! I've ran a few matches and when the heat is on I will have new faces placed on every relay if we see greatness coming. Anyhow, this "IS" the nationals and compromise on a few things have to be considered. I don't see another record target with shooter pic at this. Lol It's a good time to not offset the targets and reface a few times.
 
I agree with Mike on offsets. E-targets in general will be a BIG change for 99% of us as it will be our first time using them. My "gerbil wheel" upstairs might be able to handle a vertical offset but vertical and horizontal...too many variables to deal with....lets just swap out a few more target centers. Eric in DL
 
We haven't had any issues with our shooters using an offset on our targets. Just something you get use to.
Since I had just approximated my 1000-yd elevation prior to the two matches I shot at Atterbury with the ET's, I did not even notice that my POA's and POI's were different when I adjusted my scope. If Shawn had not mentioned this, I would have never known. These two matches were very well run by Shawn, and they were a lot of fun. Looking forward to Lodi!

Geoff - quick question. When you wrote (in part):
" . . . So you might calculate a shot position along with say an error - or area of uncertainty - of say 5mm. Or more...

So if you numerically determine an error of say 5mm, what do you do with it? It is basically saying that the shot position is x,y but it could also be anywhere within 5mm of that point.

So it really means that perhaps you expand the gauge value (3.91mm radius) by 5mm and then . . .
"

Did you mean 0.5mm?

Thx!
Alex
 
Since I had just approximated my 1000-yd elevation prior to the two matches I shot at Atterbury with the ET's, I did not even notice that my POA's and POI's were different when I adjusted my scope. If Shawn had not mentioned this, I would have never known. These two matches were very well run by Shawn, and they were a lot of fun. Looking forward to Lodi!

The shooter dials in his/her corrections and hold-offs according to what they see on the monitor instead of a spotter on a target. The offset isn't a big deal. Also a screen shot of a record target can be taken to preserve the evidence...
 
Since I had just approximated my 1000-yd elevation prior to the two matches I shot at Atterbury with the ET's, I did not even notice that my POA's and POI's were different when I adjusted my scope.........
Alex
Others that have a refined zero probably don't want to walk it in. A scope is not a surveyor's instrument.
 
Gentlemen,

I have just finished reading all the messages regarding the ET system at Lodi and other ranges. There have been people who cancelled our matches because we are using electronic targets. That is their choice completely and is ok by me. I suggest to them to go to a range that does use them and try it out - they may be very surprised they actually like it or they may not. Using the ET system is not being forced on anybody at Lodi. Some of our members do not like the system and can use the paper targets instead.

I do not know all the technical "stuff" that goes with the ET system but do know I can turn the system "off" in the Stat Office if necessary. There is still some work going on at the range and everything should be done by Sept. 23.

We are not yet full for either the Mid-Range or Long Range matches. If anyone wants to enter, please send me an entry form and fees as soon as you can. Entries close on Sept. 16, 6:00 pm. The range capacity is 192 competitors (32 targets) and six relays for Long Range and probably five for Mid-Range.

One person was asking about what to bring to Lodi besides all the shooting equipment everybody brings. Be sure to bring sunscreen lotion, bug spray (there may be ticks around plus other types of bugs), rain gear. Temps may be cool in the morning and get up to the mid-80s in the afternoon. There might be fall colors of the trees around the Lodi area and they are beautiful. A lake is close by in Lodi for anyone interested in fishing. I know some of you are staying in the cabins by the lake and will have a great time!

TJs Catering from Sauk City will be bringing lunch every day (you pay for) - brats, chicken, pork tenderloin, hamburgers, cookies (cookies are great!!) and sometimes chips. All their sandwiches are good and they also bring appropriate condiments to go with them.

Hope to see you at the Nationals next month.

Karin Liebetrau
 
Lots of good information - Thank you, Karin!

Do you allow pop-up canopies to be setup behind the firing line?

Thx -
Alex
 
Lots of good information - Thank you, Karin!

Do you allow pop-up canopies to be setup behind the firing line?

Thx -
Alex
Hi Alex,

Not at this time. There will be a lot of cars parking behind the firing at the 1000 yd line and the only place you may be able to put up a pop-up might be in the camping area or by the picnic shelter. Will have to wait and see how everything else looks before the match starts. If you have room bring it along anyway.

Karin
 

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