“Effects of rifle weight and handling length on shooting performance” Applied Ergonomics, Vol. 28, No. 2, pp. 121-127, 1997 - that is the full reference (provided in the initial post).
http://www.sciencedirect.com/science?_o ... 602e93055c
I KNOW NEXT TO NOTHING ABOUT THE BEST DESIGN (THEORETICAL OR PRACTICAL) FOR ANY TYPE OF RIFLE AND ANY TYPE OF SHOOTING (OFFHAND, BENCH, NRA, ISSF), REGARDLESS OF RULES. I FREELY CONCEDE THAT LONG HEAVY BARRELS ARE BETTER FOR ACCURACY, CONTROL, SIGHT RADIUS, and MOMENT OF INERTIA. I FREELY CONCEDE THAT A LARGER MOMENT OF INERTIA LENDS GREATER POINTING STABILITY, ALL ELSE EQUAL. I CONCEDE ALL OF THESE POINTS. I AM NOT A COMPETITION SHOOTER. I LIKE TO SHOOT FOR FUN. I LIKE THINKING ABOUT NEW WAYS OF DOING THINGS.
I am not an engineer by training. All of my opinions are opinions. Any data I cite is not mine, but was produced by others.
As a scientist by trade, I can tell you that a sample size of "N" isn't, on its own, a sole determinant of "significance." Rather, the observed effect size and the sample size together determine significance of the result. Sometimes, a result is scientifically statistically significant with a sample size of 3 per arm. Whether the result is of practical significance is another matter, but you specifically questioned the "statistical" significance.
http://en.wikipedia.org/wiki/Statistical_significance -
In the earlier post, I provided the effect size, the SD, and the statistical significance - P<.05. The P value cited in the abstract is <.0001, or a less than 1 in 10000 chance that the observed results were random.
As a former champion debater and a person who has heard our President speak for more than 28 seconds, I am familiar with straw man arguments too. A straw-man argument is an informal fallacy where the opponent misrepresents your position and defeats the misstatement.
If my assertion is indeed that "shorter, lighter rifles being better for offhand shooting" but the criterion/standard is that I must show that they "win" (NRA or other) offhand shooting, in order to be "better" then the informal logical fallacy is yours.
You can't "win" a competition class that doesn't exist. You can't win a competition class that does exist with a rifle that does not comply to the rules. The rules largely determine what "is" allowed (and therefore what is developed and built) but they can never establish the best possible offhand shooting rifle.
What "is" cannot logically entail what "ought to be" and this is also a classical fallacy with its own Wiki entry.
The is-ought problem in logic, as per Hume..."who noted that many writers make claims about what ought to be, on the basis of statements about what is" - in other words, "the rifles that dominate competitive offhand shooting events such as NRA silhouette are the best possible offhand rifles in all possible worlds with all possible rulebooks." That is sort of the Voltaire satire version of this discussion.
I was trying to illustrate this logical is-ought fallacy with a reduction to absurdity about rules determining what is best - there is insurmountable circularity in that logic. Rules determine what is allowable, but not necessarily what is best. Again, not a single home run was hit in Major League baseball this year with an aluminum bat.
Physics and ergonomics are scientific disciplines which allow theories to be postulated and measurements taken (at a somewhat different level of precision) which allow factual statements to be confirmed or disconfirmed. You can, for instance, prove that a given hitter or group of hitters can hit farther on average with an aluminum bat, rules be damned. You can posit detailed physical and ergonomical reasons to explain the observation.
NRA and ISSF rulebooks are documents which were written on the basis of practical history and arbitrary preference. They outlaw certain rifle ergonomics, seemingly for no other reason than that they are non-traditional in appearance. At least with aluminum bats, it is because they would have to rebuild so many stadiums and prevent lethal beanings.
You specifically mention biathlon shooting, but fail to note that there is a minimum weight (3.5kg) as well as a requirement for bolt-action, lever or Fortner pullback, no semiauto allowed. The biathlon also forbids optical sights, and so the benefit of a longer barrel for sighting radius remains, irrespective of ergonomics. Since you lose the quick reload the bullpup or other rear-mounted action is out - a rear-mounted bolt is just too slow and plenty awkward on dry land, let alone ski and snow. The mags are regulated, as is the trigger pull, and stock dimensions. Only hand-shoulder-cheek-chest contact is allowed, so no chin guns. The rule book alludes to stock dimensions but does not provide them.
http://www.biathlonworld3.de/media/down ... _rules.pdf
Please read this short biased history of biathlon stock ergonomics - a story of stagnation and innovation. It is shocking that they just went along with those 11lb turds for so long. A talented biathlete (an airline pilot by trade) decided he wanted a lighter stronger stock. He made a stock that was lighter and shot better. The rules were changed to allow the better stock to compete. The guy retired from flying planes and now designs stocks for a living.
http://www.eberlestock.com/original_eberle_stock.htm - note the NRA-illegal palmrest.
I have seen data to suggest that all things being equal (steel, chamber cut, crown cut, rifling, etc.) that a rigid bull barrel is inherently more accurate than a tapered barrel of the same length with an assortment of ammo types - not to say that a tapered barrel might not point or hold better ergonomically in a particular offhand gun, or have a more repeatable whip and resonance with a particular load, mated and bedded in a particular action.
I have seen other data to suggest that all things being equal, a gun with a nearer center of mass and a lower total mass will aim more stably, and with less effort, under offhand target firing conditions by an average military marksman. This is not to say that a 2lb sack of crap held close to the chest will shoot better than a ten-lb Anschutz. That would not be a valid experiment though, since more variables are changing than just the controls. I would like to take a nice barrel and move it closer to my chest so I can aim/shoot without as much muscle strain.
We have all seen historical fact that "winning" NRA silhouette rifles with "different" ergonomics have been outlawed by rules changes - this proves that competitions under the current rules do not and can not determine the "best possible" shooting rifle, only the "best allowable" rules-compliant rifle (a matter of ballistics, ergonomics, and the whim of the committees).
Just as the rules preclude using a non-tapered barrel in some classes, the rules effectively preclude using a short gun with a sufficiently-long and rigid barrel in many types of offhand shooting. This is because the stock dimensions sighting dimensions are restricted relative to the bore line. If the cheek has to be below the bore, you can't use a bullpup, and if it can't be used, it won't be developed for this competition. It will never win, no matter how well it shoots.
If bullpups or other wacky stocks were rules-allowed, we might know whether they were winning designs in competitive offhand shooting. Until that day, sure, you can just shorten a barrel to get a shorter gun, with a concomitantly nearer center of gravity, but you would lose all the benefits of having a long barrel if you do it by cutting the barrel length.
Also, you can only go from the typical barrel length (which is what, 22" or so?) down to 16" before you break a federal law, the worst type of rules-violation imaginable, because you lose the contest AND go to prison.
You aren't going to do much to either the center of mass or the moment of inertia that way.
A long barrel is also sometimes used just so that the projectile goes subsonic inside the barrel, and doesn't undergo this chaotic process external to the gun - added predictability. I don't know what the typical muzzle velocity or muzzle energy is in rimfire silhouette, so I don't know if that is factor.
The NRA rules do not preclude shorter and lighter rifles, they just prevent many of the most interesting ways to get there, including bullpups which allow for a long barrel and a shorter lighter rifle simultaneously. The ISSF has a similarly-restrictive set of rules on stock dimensions and layout for 300m and 50m guns. They restrict foreend depth, pistol grip depth, butt plate dimensions, offset and twist, barrel length, sightline height, etc.
They also use iron aperture sights, although the pinhole effect does give them some optical power (another somewhat arbitrary rule/exception). A long barrel and long sight radius are important for long range guns with iron sights. Barrel sighting extenders are, of course, banned.
I will concede no one is currently winning competition offhand with 16" fat barrels. That alone is evidence that in an otherwise rules-compliant stock, short and squat provides no advantage while incurring some disadvantage, be it moment of inertia, or some determinant of ballistic accuracy.
Long heavy barrels are great ballistically, I just think that they might not be ideal ergonomically. I have scientific data to back that up.
If you take out the ISSF and the NRA, who is left to organize competitive offhand shooting? What events or competitions can these free-style guns win?
We know that, when allowed, shooters are going to devise zany crazy stocks that shoot well (chin guns). Compare a winning bench rest stock to the rulebook for offhand NRA or ISSF - and also compare it to an unlimited bench gun, whichs is basically an adjustable semiportable barrel vise. Different guns win under different rules.
We don't know what is possible if the rules were different, we only know what dominates under the current circumstances.
It is a basic is-ought conundrum.
There simply isn't an unlimited supply of money, engineering time, or competitors to explore non-compliant firearms layouts at a high level of performance - without some organization, who can even say what the "best" performer is?
We do know that military developers want shorter guns for many reasons (other than best offhand accuracy). They want smaller guns that shoot as accurately as possible. They have a different set of constraints. However, the constraints imposed by the NRA silhouette stock layout (along with the basic advantages of longer barrels) precludes exploration of interesting ergonomic experiments in offhand shooting.
Both the FN p90 and the Magpul PDR have a wacky grip layout. I don't think they would outshoot any NRA smallbore guns, but far fewer people have ever tried to maximize accuracy while minimizing total length. However, we don't know what the "best" offhand shooting stock is, because the rules about stock layout are somewhat rigid and anti-innovation (and maybe necessarily so).
A bullpup does allow the center of gravity to be moved closer to the shooter. A shorter barrel does as well. A bullpup allows a shorter gun with a longer "heavy" barrel.
A shorter lighter barrel affects accuracy beyond aiming stability - it has a detrimental ballistic and inertial effect.
Any discussion of what could win if X rule was changed is a pure hypothetical, since the rules are what they are, and no great companies or shooters will waste their time on "what ifs" without a good reason. However, there is at least some solid evidence that bringing the mass toward the shooter is a good thing for off-hand shooting, all other things being equal.
Of course, as you initially noted and I conceded, if this is done while greatly reducing the moment of inertia, it might hurt pointing stability overall. However, you can shift mass to the extreme rear of the gun and move it forward too, which doesn't move the center of mass but increases the moment of inertia. They are coupled, but there is a degree of freedom. Similarly, you can make a gun both lighter and with a nearer center of gravity and the same moment of inertia as before.
The chin gun allowed downward pressure on the buttstock, which allowed several things, including a reduction in the amount of isometric muscle tension necessary to hold the gun and point stably. The chin was basically a third hand on the stock. It may have also improved sight alignment too, but this was one ergonomic effect, similar to just moving the mass closer to the shooter.
Unless a person has the time and money and knowledge to develop a new type of gunstock, they never will. No single developer can match the collective creativity and resources of the entire sport. A relative minority of shooters developed the chin gun, and as I understand it, a relative minority of competitors and officials had it banned. I don't think that was a high point in the history of silhouette shooting.
It isn't my sport and I don't make the rules, but I would think that the rules should favor performance and creative thinking. I think it would be cool if there was a class where anyone was able to shoot anything that is either 1)commercially available) or 2) fully in the public domain (ie, copyable and improvable by other shooters). This is my statement of what "ought" to be, and it is not logically entailed by what "is" the current state of the sport. Sure, have dimensions, weight classes, calibers, etc, but have an unlimited class to allow real innovation. Some great shooter will still win the class with a factory rifle.
If a level technical playing field is all that matters, then perhaps everyone "ought" to shoot the same gun and the same ammo. Perhaps no sponsorship should be allowed either.
All of the major manufacturers build to the limits of the rules, but sometimes optimality is restricted by patent law and heavy-handed negotiations.
I have seen no less an aficionado as Dieter Anschutz state in print that electronic triggers are unneccessary because mechanical triggers have as good a locktime and better reliability. When asked a follow-up question about electronic ignition (with superior locktime), he just said that the reliability was poor. This is a man who has made a ton of money off of things staying just they way that they are - he has no reason to allow some upstarts to change his game. He couldn't license the electronic ignition from Krico, so he forbade his sponsored shooters from shooting it at risk of losing his sponsorship. Without that support, the idea died on the vine, even though the shooters had some personal bests with the electronic ignition DIANA .22LR prototypes before he issued his ban. He doesn't tell that part of the story in the interview.
http://www.gun-tests.com/performance/nov96anschutz.html
Anschutz wanted to use it, but he couldn't negotiate the rights, so he used political and financial power to kill it.
