Does LV shoot better than HV?

K

KimZ

New member
Looking over historical scores of air rifle benchrest matches I get the impression that LV does better than HV. But most matches are small, with a relatively low number of targets to compare. The recent WRABF 2015 air rifle benchrest competition provided a large number of target scores, which are now posted here:

http://www.benchrestbulletin.net/drupal2/node/2928

Statistical comparison asks whether differences in mean scores were unlikely to have occurred by chance.

I imported the 2015 World's individual target scores into a statistical software package (Minitab), and compared the mean score for LV and HV using a two sample T-test:

Two-sample T for LV vs HV

N Mean StDev SE Mean
LV 264 239.35 6.38 0.39
HV 270 237.69 7.15 0.44

Difference = mu (LV) - mu (HV)
Estimate for difference: 1.66338
95% CI for difference: (0.51201, 2.81476)
T-Test of difference = 0 (vs not =): T-Value = 2.84 P-Value = 0.005 DF = 527

>>Mean LV score was 1.66 points higher than mean HV score, and the difference in means is highly unlikely to have occurred by chance alone (probability = 0.005).

An alternative explanation would be that since the event occurred over 3 days, differences in wind/weather could have caused this difference. If the same results are seen at different matches, then the conclusion that LV > HV is on target.
 
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Interesting question for sure! I don't have an answer, either made up or perceived, but it's an interesting question nonetheless. If the difference between LV and HV is weight only you'll need more data...and not have a preconceived opinion because it's likely gonna be close. Then, you need to determine if folks are shooting LV rifles in the HV class. I don't know if you can do that..just saying. I know if I had a really good LV rifle and could shoot it in the HV class I would...unless I had a HV that shot better.

Yes, I know...go read the rules!

I need to attend an air rifle match so I'll know a little more what I'm talking about...given I can't help but chime in now and then. Does anybody know the closest match to Spring City, TN?
 
Score differences between HV and LV guns, my take

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I think LV guns are intrinsically a very slight bit more accurate than HV guns, if the match is INDOORS, but if wind becomes much of a factor, the edge shifts to the HV side. But I also feel that ANY well set-up benchrest tuned airgun, whether 7fpe or 30fpe can shoot 250's indoors, and that the real game IS outdoor shooting, since its the element of wind that reveals the skill.

Just looking at past outdoor scores won't always show the impact of this wind vs class effect, because its not always clear that in more cases than not, the LV class is favored by being the earlier relay. This practice is common in regular one-day club matches, with LV going in the morning, than HV, and finally Open in the afternoon. Its most likely for breeze to turn to wind as noon approaches. I agree totally with this schedule, since it tends to even out the power differences in the classes, but it does skew scores a little if the Monday morning guys don't consider it.

BIG matches like the World's, where each class may shoot pretty much all day don't have the class bias so much, though the "early start" competitors of the day are usually the luckier ones (yes, luck does enter the fray some in this game).
 
Hi Guys,

Interesting observations, but first of all you must understand the rules (assuming you are talking about the recent WRABF World Championships).

The LV class is set at 12ft/lbs, the HV class is set at 20ft/lbs.

That makes a HUGE difference.

A comparison between the two cannot be made, they are what they are. Indoor shooting is a different matter.

Brian
 
Imho if there is no or little wind lv is more accurate, in saying that if u shoot lv in hv class and there is wind you will loose.
 
therealld said:
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I think LV guns are intrinsically a very slight bit more accurate than HV guns, if the match is INDOORS, but if wind becomes much of a factor, the edge shifts to the HV side. But I also feel that ANY well set-up benchrest tuned airgun, whether 7fpe or 30fpe can shoot 250's indoors, and that the real game IS outdoor shooting, since its the element of wind that reveals the skill.

Just looking at past outdoor scores won't always show the impact of this wind vs class effect, because its not always clear that in more cases than not, the LV class is favored by being the earlier relay. This practice is common in regular one-day club matches, with LV going in the morning, than HV, and finally Open in the afternoon. Its most likely for breeze to turn to wind as noon approaches. I agree totally with this schedule, since it tends to even out the power differences in the classes, but it does skew scores a little if the Monday morning guys don't consider it.

BIG matches like the World's, where each class may shoot pretty much all day don't have the class bias so much, though the "early start" competitors of the day are usually the luckier ones (yes, luck does enter the fray some in this game).
Click to expand...

I agree with Larry's explanation here. Regarding the Worlds in Brisbane - conditions were generally better in the mornings and more difficult in the afternoons.
Day 1: Morning - LV 1st target. Afternoon - LV 2nd target.
Day 2: Morning - LV 3rd target. Afternoon - HV 1st target.
Day 3: Morning - HV 2nd target. Afternoon - HV 3rd target.

LV: 2 targets were shot in the mornings and only 1 in the more difficult afternoon.
HV: only 1 target was shot in the morning and 2 in the more difficult afternoon.
Imo the reason why the LV scores are marginally better than HV scores.

Paul.
 
Good point about the possibility of different wind conditions for World's LV and HV scores.

However there is data that is controlled for wind: Open Grove match scores. Open Grove matches mix classes at the same time. ie, LV, HV, OP can all shoot together over the same 3 relays, and therefore under the exact same wind conditions.

Searching this site, I found historical Open Grove 1st match scores that had both LV and HV shooting at the same time over the past year or so. I imported individual scores into the stats software, and compare mean target scores as before:


N Mean StDev SE Mean
LV 71 240.54 6.56 0.78
HV 54 240.85 6.29 0.86


Difference = mu (LV) - mu (HV)
Estimate for difference: -0.316641
95% CI for difference: (-2.608878, 1.975597)
T-Test of difference = 0 (vs not =): T-Value = -0.27 P-Value = 0.785 DF = 116

>>NO DIFFERENCE!

This data set has fewer target scores but is a better test, because it controls for wind effects (N is high enough to have shown a difference had one existed).

I can go back further and add to N but this is strong evidence that HV and LV shoot the same outdoors, and the conditions at 2015 Worlds were harder for HV
 
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Kim,

I think you may have to go a lot deeper than just LV, and HV rifles being responsible for the scores that were produced.

1. So far, your analysis is assuming equal competency for all shooters.
2. It's also assuming that each shooting position is equal (bench).
3. It assumes that each rifle is equally capable in wind.
4. It assumes that each competitor mentally manages tough conditions equally.
5. It assumes that each competitor is equally brave in both classes. Personally....I used to take a lot more chances when shooting HV. That is something I have been working very hard to fix.

There are probably a whole lot more things to consider as well.

Mike
 
Mike

I agree there could be biases within a given match, but If N is high enough over many matches these effects should wash out. ie, shooter variables (skill, bench position, composure, toughness, bravery) ought to even out over many targets - unless there are hidden persistent effects such as "the best shooters prefer LV" or such. The same is true for pellet selection, time of match, state of the economy, and who is president. ;)

The high N of the World's did show a difference - in conditions.

A better test would be prospective: Two shooters of roughly equal ability, shooting HV and LV outdoors at the same time, then switching rifles back and forth for many targets. Then comparing Bob's 40 HV to his 40LV, and Ted's HV to his LV.

Failing that, retrospective studies like this don't support the claim that HV and LV shoot differently outdoors.

Kim
 
I do a fair amount of shooting

I am tending toward using my HV gun for Open class matches as well, since the only advantage it seems to have is at 50yds. BUT, when I have tried using my LV gun for both LV and HV, I have done worse in HV, EVEN at Open Grove. I know many, if not most club matches have mixed relays, but I seem to recall the serious matches at Open Grove ran the LV and HV classes in different relays.

See, IF the guns were TRULY equal even across conditions, there would be more "one gun" competitors using the same gun for both classes, but the FACT is, the conditions are a large enough factor that one tends to shoot the LV gun early if possible.

Another issue is bench position, which CAN make a difference on certain ranges, so if competitors get a favorable position, and are not required to relocate each relay, a significant advantage over a less favored competitor will accrue.
 
Up until a few months ago....I would have (and did) chosen my LV gun for any condition and class. For me, that is no longer the case.

A 3 ring holdoff for my HV gun is a 2 ring with my Open, and 5-6 for my LV. Currently, my LV, HV, and Open setups are equally reliable in the wind, and will shoot nearly equal indoors .....so despite any statistical analysis that may imply that I am likely to shoot the same score with any one of them, I am going to shoot the class designated rifle for each discipline this year at the Nationals.

I will let you know if I end up regretting that decision.:D

Mike
 
michaelthomas said:
.....so despite any statistical analysis that may imply that I am likely to shoot the same score with any one of them, I am going to shoot the class designated rifle for each discipline this year at the Nationals.

I will let you know if I end up regretting that decision.:D

Mike
Click to expand...

I think that would be a wise decision Mike. Statistics are a wonderful thing, until the wind start's to blow, then ballistics rule.

Brian
 
AHA! There's a pellet speed difference!

Be careful Mike..and don't forget which one you're shootin'! Should be easy if you base your hold on a sighter shot...and I don't see why you wouldn't do just that if you were shooting anything.

OK, back in my hole for a while - I'll check the schedules for that airgun match I mentioned. :)
 
Wilbur said:
AHA! There's a pellet speed difference!
Click to expand...

Not so much a speed thing Wilbur, but a weight thing.

In general a LV rifle will use a 7.9 to 8.4gr pellet at around 780fps. A HV rifle will generate the same speed (ish), but using a 13.5gr pellet (for example). A huge difference in ballistic performance.

The problem the original poster has with trying to apply statistics to the recent WRABF World Championships, is he has no way of knowing who actually shot a HV rifle in that competition. To be fair it was most probably the majority, but a reasonable percentage will have used LV rifles.

Brian
 
I was there and i reckon 2/3rds of the shooters still used their LV rifles for HV and also by the third day of shooting Air rifles on the same range you tend to improve your scores as you get to know the wind patterns , So you should expect to see some improvement in Aggregates So your number crunching stats aren`t valid for this event
My opinion is we should be shooting 50m with the HV class its kinda a waste of time at 20m

Dave Keen
 
Using some different Open Grove match scores (again with LV and HV shot simultaneously), this time LV out-performed HV significantly:

Two-sample T for LV vs HV

N Mean StDev SE Mean
LV 90 235.9 14.6 1.5
HV 33 230.2 11.2 2.0

Difference = mu (LV) - mu (HV)
Estimate for difference: 5.70404
95% CI for difference: (0.75158, 10.65650)
T-Test of difference = 0 (vs not =): T-Value = 2.29 P-Value = 0.025 DF = 74

I didn't use these matches in the prior comparison because most were shooting LV (90 LV vs 33 HV).

Note that none of the three studies show HV as more accurate outdoors than LV, despite higher ballistics which *should* - in theory - shoot better in windy conditions (especially Open Grove).

The question for those who believe there is no relevance to actual historical scores: What is the evidence that outdoor accuracy increases with fpe?

Remember that if you have two rifles and the HV shoots better than Lv, that may only mean that your HV is a better rifle but the accuracy isn't due to fpe.

(I should emphasize that my goal is to see whether statistical tools can be applied to our sport to improve understanding :confused: )
 
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Classic example of the old saying, "Figures lie and liars figure". I truly appreciate your analysis but there are things in this game that are difficult to explain. Part of the reason may be that we do not even know what factors need to be better understood. Are you considering caliber differences that are being shot in HV?

I heard of another example where targets were pulled out of the garbage, at a different California range, to be scored a second time, or was it a third time? Now that would really skew your statistics.
 
Kim,

I think it would be more interesting to me if you studied the probability of scores over each class considering proposed holdoffs based on the wind drift associated with each power level.....independent of the shooters decision, first. You could use a given mph of wind and assess holdoffs for each class.....then add in "mistakes".

It's clear that if a person made zero judgement errors when shooting..... power level would be irrelevant.

As you know....I have already done a "real world test" of power level in specific wind at my range. I used 3 equally shooting indoor rifles that were zeroed indoors....one of each power level (LV, HV, and Open). I got 2 other guys to help me shoot. We shot at the center of the bull, and pulled the triggers at the exact same times for each shot. Looking at the scores, it was no real surprise that the higher power level guns always produced the best scores in any condition.

After that.....you have individual judgement that gets factored in. I could consistently outshoot my buddy with my LV gun....even though he was shooting the Open gun. The really disturbing thing for him was that he could not match the open class scores that were shot by just holding in the center..... no matter how hard he tried. He made poor decisions on the wind velocity and direction. He could score better by just pointing at the middle.....but for some reason he wouldn't. He always believed that he could do better by applying correction....but he was wrong.

When I compared my "best judgement" scores to my "no holdoff" scores.....I could always stomp the crap out of the "no hold off" ones in LV. I could always beat the HV scores, too.....but the margin was substantially smaller. I could only beat the Open scores maybe 75% of the time. That was a bit of an eye opener for me, and has influenced the way I shoot to some degree. This was done in conditions that were not too tough compared to Open Grove.

When my daughter came out with me to Open grove.....she shot pretty well in LV. She beat a bunch of experienced shooters....having no experience of her own. I zeroed her scope for the average condition, and she just pointed at the center. According to her, she made no effort to add in any additional correction. I think she shot a 720.

Mike
 
WRABF Championships.
Australia Team A won the teams' LV air with 2194 - 5 points clear of USA Team A 2nd with 2189 ; and RSA Team A 3rd on same score as USA.

USA Team A won the teams' HV with a score of 2194; same as Australia A's winning score in LV, but in what was considered overall worse conditions.
USA B was 2nd with 2187, Brazil A 3rd with 2182.
Australia A finished 6th with 2178 with same team, 16 points behind USA Team A.

So far as I recall, USA all shot HV rifles as, I think, did Brazil.
Aus A shot LV rifles . Their score 2178 reflected comparative conditions considered to be worse than in the LV event. Two sessions were afternoon, whereas in LV two sessions were morning.

In summary it would appear that HV power ruled in difficult swirling wind; with Aus team score reflecting less ability to cope with more difficult conditions using LV rifles.

Benches and relays were rotated throughout the tournament.

Australia has never shot Air HV class in their team trials. That is about to change. ... Kind regards, Harry.
 
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OK, think I've got it now. Both LV and HV run at the same speed, give or take, but the HV pellet is heavier....right?

Are the speeds controlled by the rules?
 
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