Scoring wrinkle ... can of worms?

T

therealld

Guest
We have been shooting airgun benchrest now for a couple years, and, though I seem to be the only one who has commented on this, I feel its a valid topic of discussion.

Prior to switching to 50 yards shooting, we fired from 25yds and used "traditional" circles with scoring either "best edge" or "worst edge", using the then-standard scoring plugs with .177 plug and .223 scoring circle on the plug. At this time, we were all shooting either .177 or .22 cal.

The we switched to shooting at 50 yards and scored for group size, center to center. We now have guys shooting .177, .20, and .22 cal air rifles, and we have traditionally been subtracting either .177, .200, or .223 from the outside to outside distance to arrive at ctc group size.

BUT, I've been noticing that there is damned little difference in the ACTUAL holes made in the target paper no matter if its .17, 20, or .22, and I'm realizing we have likely been unfairly rating the .22's (at least). If we use the regualr roundhaed pellets that seem to work best nowadays, it appears the actual holes made range between about .150" for .177's to .165" for .22's.

See, compounding the issue of apparent hole size, is the FACT that a .22 airgun only has a bore size or around .211" or .212", with a groove size of about .216". Yet we been allowing .223! Yes, ".177" pellets measure about .180"!

So sadly, our ctc groups as calculated are really a little larger than we thought, even if only by around a millimeter.

I'm now thinking to abandon the ctc calculating and simply go edge to edge, no trying to figger where the grey tells you the TRUE pellet edge was, no allowing for caliber at all, just measure and write it down.

I think, in the short term, the difference will only matter when looking back to older "records", and in the long term, if there IS a long term, we will simply be reporting more accurately.
 
Widest part

If you measure the widest part of the pellet, use will get the correct size to subtract from you CTC measurement.
 
You need a scoring reticle for measuring group size. Only problem is I don't know if anybody makes a reticle that has a .17 and .20 cal circle. The centerfire reticles have 22cal, 6mm and 30 cal circles since these are the most common sizes.
 
As I said in the post ... I don't belive this is true (widest part of pellet, yada,

Fred J said:
If you measure the widest part of the pellet, use will get the correct size to subtract from you CTC measurement.
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I know its an EASY way, and its the way most folks have done it for ages, but I'm now thinking its not REALLY correct at all!

Say a .177 cal gun makes a group that measures .500" from edge to edge and we subtract one (measured) HOLE DIAMETER of .150", giving a ctc figure of .350" ctc, and then we come across a group fired by a .22 cal gun that also measures .500 edge to edge, and we subtract a HOLE DIAMETER of .165" for a .335" ctc.

Now, using current methods, we figure the .177's group of .500 by subtracting .177 and get .323" ctc, and the .22 cal guns group of .500" edge to edge comes out .277" ctc.

Now, measuring PELLETS, at the widest part IS fairly meaningless, since they vary so much before firing, but are always smaller after a trip through the bore.

I really think if we are going to measure groups, we should measure what we actually see, not some of what we see, and some of what we THINK seems fair because we've dunnit that way all along.
 
I've had this very same discussion a bunch of times with folks that use the subtraction method and I've never agreed with them. I measure what I can see on the paper because no matter what you theoretically subtract in reality it stays the same physical size. A decent set of calipers or a good thin steel rule and good quality paper to print your targets on and your done.
Sometimes the KISS rule is the best choice.
Doug
 
Rifle caliber does matter. I shoot a 30BR in group matches. A tiny 30BR group makes a BIG hole. If the scorer didn't take into account the caliber of the rifle I wouldn't have a chance not to mention that it would be completely unfair. The measurement you are supposed to end up with is center to center, not edge to edge. This is why you need a scoring caliper that has the correct diameter circles inscribed on a clear plastic plate.

http://www.neiljones.com/html/target_measuring.html

Hart also has a nice one on page 8 of their catalog. Neither of these will work for an airgun because they don't have a 17 or 20 cal circle but they are examples of what is needed to fairly score a group match. The difficulty in accurately and fairly measuring groups is why score shooting is so prevalent.

IMO as a match director you must make every effort to run a fair match and this includes having the proper tools and skill to accurately measure groups fired by any caliber you allow to shoot in your matches.
 
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So you are saying I'm running an unfair match?

I say to this ... go pound sand buddy. My observation is the standard scoring method being used by nearly every airgun BR club that allows different calibers didnt seem fair. It was clear that actual measuring of the widest shots from inside of one to outside of the other for SURE gave consistently different, and obviously incorrect readings as compared to measuring outside to outside, and subtracting one caliber, as is generally done. The results consistently favored the .20 and .22 caliber over .177, and favored all calibers compared to real world measuring rather than assuming the holes were the size of the pellets.

Our option was to try to give the closest thing to actual observed groups practical. We use a dial caliper with grads in thousandths of an inch, And most of us agree that in a perfect world, a really skilled person could measure between the inside of one hole to the outside of that other and get the EXACT ctc distance, but experience was showing it more difficult to measure from inside of one hole to outside of another, so we measure outside to outside, then subtract an approximation of the apparent hole sizes actually left by the pellets.

The method we use is as fair as we can practically use at this time, and we club members are ok with it until we see something better, which we are certainly open to trying so long as its reasonable. We have volunteer scorers that are also trying to shoot AND score, and we rotate scorers from match to match so its not such a burden on em. I think a digitizer board would be great, but I no longer own one, so we are doing what we can to have a good shoot.

re:

crb said:
Rifle caliber does matter. I shoot a 30BR in group matches. A tiny 30BR group makes a BIG hole. If the scorer didn't take into account the caliber of the rifle I wouldn't have a chance not to mention that it would be completely unfair. The measurement you are supposed to end up with is center to center, not edge to edge. This is why you need a scoring caliper that has the correct diameter circles inscribed on a clear plastic plate.

http://www.neiljones.com/html/target_measuring.html

Hart also has a nice one on page 8 of their catalog. Neither of these will work for an airgun because they don't have a 17 or 20 cal circle but they are examples of what is needed to fairly score a group match. The difficulty in accurately and fairly measuring groups is why score shooting is so prevalent.

IMO as a match director you must make every effort to run a fair match and this includes having the proper tools and skill to accurately measure groups fired by any caliber you allow to shoot in your matches.
Click to expand...
 
therealld said:
So you are saying I'm running an unfair match? :
Click to expand...

I was mostly responding to Doug's post but you are more than happy to get your panties in a wad. :rolleyes:

If you didn't have questions about your scoring method this thread wouldn't exist.

I have been watching an excellent scorer use a reticle to score our CF group matches since 07. He is fast and everyone has complete confidence in the results. I have come home and scored my targets with a caliper and the differences between what I come up with and what the reticle produces can be big enough to show me that faking it is faking it.

A proper Air Gun reticle would have circles that match the OD of a fired pellet of each common caliber. Nobody makes one but it would be something that would have a small market if someone offered a kit for sale.

Measuring tiny groups accurately and fairly is not easy even with good tools. Not having good tools will make anybody doing the scoring feel less than confident in their work.
 
So Ray,

You claim this "problem" s a result of me bringing it up, perhaps becuase yo wanted it left buried?

You are saying I am running unfair matches. But its also clear you have a strange definition for the word "fair". To me, running a match UNFAIRLY would imply an element of dishonesty, or at least ignoring of protocol that would result in more fairness.

The fact you believe that there ARE no reticles appropriate for use with typical calibers used for airgun BR matches that score by group sizes for sure says you feel ALL such matches are unfair.

And, the FACT that you are unaware that the holes produced by common round-nosed design pellets in airgun targets is considerably smaller than the reticles you claim would be appropriate expresses a degree of ignorance that is, though common, very unfortunate.

Your claim as to the efficacy of scorers you have observed using the reticles you tout and the admission that you feel use of calipers is "faking it" reveals that:

a. You may not be very skilled in use of precision calipers, and unaware that its easily possible to test the skills with such a caliper by measuring and recording the diameter of scoring rings of an unfamiliar target, then comparing the results with the known spec's. for it. My experience has shown decent dial or digital calipers to be generally repeatable in the kind of application we are discussing to plus/minus .002".

b. Our matches consist of thirty groups fired per competitor, and thus required 240 groups to be measured (last weekend). Its not rocket science to realize that so long as the same scorer checks all the groups, things are going to average out if a shooter is firing thirty groups, but that its a LOT of work to look at, select, and measure between 480 individual edges.

Anyhow, to reiterate, the "problem" is the use of scoring methods that rely on rings that are larger than the true hole sizes, or the application of rules that allow for applying a factor for caliber size instead of true hole size. Our club is attempting to get around this issue, as well as find a faster and hopefully more accurate scoring method that doesnt tax our resources beyond our limits.
 
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All I have tried to do is show some examples of how other shooting disciplines address the problem of accurately measuring groups but what I get for my effort is a bunch of synthetic fury over imaginary slights. Fortunately this kind of bs is never in evidence at an actual match but is in wide evidence on the internet although on this site it's mostly been seen in the rimfire section until now.

Good luck with your endeavours. :rolleyes:
 
Scoring for points vs groups....what method(s) apply...???

1. Calipers..??
2.Plug gauges..??
A. Inside plug gauges..??
or
B. Outside plug gauges..?

3.Templates./reticles..??

4.Might be easier to make a "hole" template ranging from 1/4" to 1" in 1/8" increments and apply point value by group(hole template) size. No points for groups larger than 1".

A Pickett Circle Master template would work. And for the anal types,it has holes down to 1/32" increments...lol..
 
Yes, well, I'm aware of all those methods, and pretty familiar with a few

But as you may recall, we had a TIE for first place two matches ago using the aggregate of 30 groups as measured with a dial caliper and I suspect using a circle template with much larger increments than the roughly plus/minus .002" we currently use will not give the degree of precision that can satisfactorily tell us who is doing precisely better or worse.

I have reviewed the methods currently in use by other target shooters, and, while I'm not arguing their appropriateness for the applications they are used for, I feel none would provide what we need with respect to practicality in the game we currently play.

I do have a few ideas that may gradually allow us to achieve faster and more accurate group size determinations, and I have the evaluation plan more or less mapped out for us in my head.

I'm going to contact you and some of the other guys and run the ideas by and try to get some additional ideas and feedback soon.
 
How in H E double hockey sticks...

can a 223 pellet make a hole that measures .165...?
Are you guys only measuring the little piece of paper that is missing after passthrough?
It doesn't sound to me like the whole...of the pellet hole is being measured!
 
first off, we don't use pellets that are .223"

I measured a lot of em, and they are .216". But yes, the "hole" is the actual part with paper missing ... I know many, including, I guess, you would prefer to "squint yer eyes" and use imagination to fill in to where it seemed the hole WOULD stretch out to if it were a full caliber size, but the actual "hole" measures, at BEST, .165" from what I can see.

Try this simple test ... get a regulation airgun bb' which is a fair bit smaller than a .177" pellet in diameter, and try to drop it through a pellet hole ... no, not a .177" pellet hole ... a hole made by a .22 pellet! Not even close!

I have a 3" long hardened steel reamer blank that's .172" dia. , and has a gradual tapered leade for near 1/2" and it won't fall thru a hole made by any .22 pellet we use in our matches on our targets ... you can even start it in in the hole, then jiggle the target quite a lot and the in doesn't fall thru!

Now, I was a precision machinist for many years, and the way we categorized and measured hole sizes was by the size gage pin that would just fall in, or at least fall out of with a bit of shaking. If my boss said, put a quarter inch hoie in this ... and it was a piece of soft plastic, or rubber, I'd KNOW i was going to need an oversized drill or reamer, or even grinding wheel on the piece after freezing it to get a hole the actual size he wanted ... a fool who just ran a 1/4" drill thru and argued it was therefore a 1/4" hole would be gone that day unless he learnt pretty quick!
 
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i just find it hard to believe that a .216 pellet can go through a .165 hole...without leaving a distinguishable trace of it's full diameter...but maybe it can. :)
 
Holes 'close' up...

...by time targets collected,put on table on top of each other...with a paper weight...so measuring with caliper is tough at that point.

Just look at the back of a target.
 
wrinkles !

there is no way anyone can whith any accuracy measure a round pellet hole punched in a paper target with a caliper piriod...!! no way no how. the big boys all use a scoring plug and have been doing so for ions . its the only fair way to measure a set size hole. a .177 cal should be measured with a approved .177 scoring plug and so on for .20 and .22 cal. if you can't buy them there very easly made ... gee git on with it..:)H.B.
 
deliterman said:
there is no way anyone can whith any accuracy measure a round pellet hole punched in a paper target with a caliper piriod...!! no way no how. the big boys all use a scoring plug and have been doing so for ions . its the only fair way to measure a set size hole. a .177 cal should be measured with a approved .177 scoring plug and so on for .20 and .22 cal. if you can't buy them there very easly made ... gee git on with it..:)H.B.
Click to expand...

Calipers ok for scorng groups...because same scorer/method applies across all our targets...so it is fair...

LD is looking at methods to reduce time for scorer...that we could all agree on at his matches..so he is trying different things...he has plugs and mentioned that,btw
(Take 8 shooters x 30 groups each.. (3 shots/bull) and that is 720 holes...)

In your case numbers less...8 shooters/400 holes assuming BR50...
 
Can of worms ??

I just had a thought and maybe this has come up before - y not just shoot 2 shots at the target ,all the otheres don't count anyway.your just looking for the extream spread.and all that takes is two. what do you think?? that would save you a lot of time scoreing huh ? btw where are you last match scores posted ? happy trails.H.B.:)
 
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