Vibration Reduction System: Defined

BenEnglishTX · Post by **BenEnglishTX** » Sat Sep 29, 2012 9:01 am

Spencer wrote:6.6.3

Thanks. I looked it up. I'll refrain from commenting on what appears to me to be suboptimal wording since I don't have any experience from which to judge how and when this rule is actually applied.

jhmartin · Post by **jhmartin** » Sat Sep 29, 2012 9:37 am

There is a meeting this week in Munich to polish the rules a bit more.
I've forwarded the "active" comments on to the US rep. (Gary Anderson)

His reply back:

We're aware of this concern. The intent is not to include "passive" weights in this prohibition.

If you have a solution for the wording, send it to your ISSF rep or post it here and we can make sure they see it.

Rover · Post by **Rover** » Sat Sep 29, 2012 12:12 pm

Better get the wording right or some schmuck somewhere will certainly misinterpret it to your detriment.

Just see "The Law of Unintended Consequences."

ShootingSight · Post by **ShootingSight** » Sat Sep 29, 2012 10:58 pm

Personally, I am very much in favor of people pushing the boundaries of rules - that is an element of being competitive, just as much as practicing, or learning a technique to establishing a sight picture.

john_almighty · Post by **john_almighty** » Sun Sep 30, 2012 5:29 am

I think the rule wanted to mean something like this product from mannel... But their ambiguity in defining it has opened it up for a wider interpretation

http://www.maennel.at/shop/product_info ... 2cdd731400

ghostrip · Post by **ghostrip** » Sun Sep 30, 2012 6:38 am

the mannel system from what i understand from the picture is passive. and looks like the weights of pardini pistols (weight plus springs). they operate after the shot is released. the adjuster just controls how much the springs are compressed.

BenEnglishTX · Post by **BenEnglishTX** » Sun Sep 30, 2012 9:01 am

john_almighty wrote:I think the rule wanted to mean something like this ...

That thing is just a barrel tuner. Hundreds of variations on that theme have become standard equipment in the benchrest world, both rimfire (where they first caught on) and centerfire.

Given that the preliminary wording refers to devices that are in play before the shot is released and given the quote from Gary Anderson ("What we are really concerned about is someone trying to use the technology now common in more advanced cameras to achieve hold movement reduction."), I can't imagine that the device you linked to would be touched by the new rule.

For that to happen, some awfully bad definitions of terms would need to be used and then the rule would need to be interpreted rather perversely during competition.

Grzegorz · Post by **Grzegorz** » Sun Sep 30, 2012 3:02 pm

BenEnglishTX wrote:
john_almighty wrote:I think the rule wanted to mean something like this ...
That thing is just a barrel tuner.

Rather not... It is usually attached to the stock...

... I can't imagine that the device you linked to would be touched by the new rule.

Indeed, as more as it gives nothing, but surely looks great! :-)

BenEnglishTX · Post by **BenEnglishTX** » Sun Sep 30, 2012 8:41 pm

Grzegorz wrote:
BenEnglishTX wrote:That thing is just a barrel tuner.
Rather not... It is usually attached to the stock...

I must disagree.

First, the ad copy on the linked page is explicit that it's a barrel tuner. To wit: "With this working Absorber system (similar to the air rifle absorber) the vibration behavior of the barrel muzzle can be reduced and affected positively."

Second, barrel tuners can be mounted anywhere. It's true that the easiest, most direct, most common, and probably most effective way to mount them is directly to the barrel, close to and extending beyond the muzzle. However, the same results can be achieved by hanging a tuner further back on the barrel, on the stock, or anywhere on the rifle. Attaching it directly to the stock, as in this case, tends to mitigate against effectiveness unless the stock is quite rigid and bedded to the action solidly. However, it does make the thing easy to attach to pre-existing stock fixtures. If the stock is all-metal, then it might also be effective. I have no idea since I have no experience with this type of tuner.

On the other hand, maybe they just sell them because they look cool. I know you were joking about this but you may well be correct. Getting a simple tuner properly set up is sufficiently difficult (they can utterly *destroy* accuracy if they're set up wrong) that I can't imagine the amount of testing required to set up the Maennel design. Without experience with it, I certainly can't rule out the possibility that it might be a wonderful thing that every shooter should own. However, even without that experience, just by looking at it, I can definitively say that it is an object of pure joy for shooters who enjoy tinkering with gadgets as much as they enjoy shooting. And I think we all know shooters who fall into that category, don't we?

Grzegorz · Post by **Grzegorz** » Mon Oct 01, 2012 1:37 am

First, the ad copy on the linked page is explicit that it's a barrel tuner. To wit: "With this working Absorber system (similar to the air rifle absorber) the vibration behavior of the barrel muzzle can be reduced and affected positively."

Paper is very very patient...

OK, the usefulness of such gadgets is a very interesting topic, however well beyond this "ISSF Rules" topic, so I do not want to continue the discussion.

In my opinion - as a judge and physicist - such passive devices should be allowed. First of all, it supports the scientific development in our sport, secondly, it gives shooters and coaches a possibility to be searchers for better results - means work. And I am very glad, that Mr. Gary Anderson stated it will not be prohibited.

Concerning "definitions" given in the rules... I have an impression, that we try to define everything very very precisely in our rules, and we have been caught in a trap. We do not give any space for jury members to decide. As a jury member I just need know rules. I have been a jury member during some WCups since three years and I NEVER met situation I would be obliged to DECIDE anything, to JUDGE anything. Just have a rulebook, know it and have finger to point the appriopriate rule number to the shooter or his coach. If judges are mistaken sometimes, we try to prepare a more precisely written rule. And so on... Rules are more "precise", so everybody expect they describe EVERYTHING (!). And there is always somebody who finds another interpretation of any sentence, and then we try to make it MORE precisely. That's a devil ring...

Watch soccer, do you see a difference? Of course, would be funny... I know... But seriously, why we stress "everything must be described in the Rules"? IT CANNOT. Write a general rule, interpret this by the ISSF Technical Committee and let a Technical Control Jury to do their job.

robf · Post by **robf** » Mon Oct 01, 2012 7:07 am

BenEnglishTX wrote:
luftskytter wrote:And why don't you just have a look at things like "steadicam" :-)
Having a little experience with Steadicams (not the pro models but models like the JR), I've often wondered why free pistols don't hang below their grips. After all, FP is supposed to be a bastion of "no rules, use the best pistol for the job".

So, obviously, when electric triggers came along that could be actuated by a switch held in the off hand they were welcomed with open arms.

And when sights that used mirrors were developed, they were lauded as advancing the state of the art.

Oh, wait... :-)

All kidding aside, some 30 years ago I rented the lightest camera gyro I could find and bolted it to the bottom of an XP-based silhouette pistol. The idea showed promise but the whole contraption was so heavy it was unusable. There was no way to make weight under the rules and there still isn't when using traditional Kenyon gyros that look like this:

If the much lighter stabilization mechanisms used in modern cameras are actually useful to steady pistols, I feel sure someone in the silhouette world will start using them soon if they haven't already.

I have actually seen a video of an American FT shooter using one of these.

Whilst FT is in the "unlimited" range of shooting sports, there's a few who don't understand that it's still meant to be a test of marksmanship, not equipment, and these are the people who effectively demand that rules are made.

Sparks · Post by **Sparks** » Mon Oct 01, 2012 7:09 am

Received by email:

Thank you for your inquiry regarding the new ISSF rule prohibiting "vibration reduction systems."

The ISSF is still working on the final wording of this rule, but the ISSF intent is to prohibit the use of any device or system that would artificially reduce, slow or control the movements or oscillations of a rifle or pistol before the shot is fired. This rule is intended to preclude the application of anti-vibration technology now used in photography, for example, to rifle or pistol shooting This rule will not affect passive means of controlling gun movements such as barrel weights and it will not affect any existing technology that stabilizes the rifle or pistol after the shot is fired. It should also be noted that ISSF Pistol and Rifle Rules already prohibit the use of compensators, muzzle brakes or other similar devices that could control how the rifle or pistol recoils during the shot.

On this basis, the compensators on air rifles and pistol are not activated until the shot is fired and would remain legal. Barrel tuning and bedding systems have nothing to do with rifle movements before the shot and would not be affected. Passive systems like barrel weights are specifically excluded. Barrel ports on rapid fire pistol have been illegal for several years and this new regulation would not change that.

With best regards,
Gary Anderson
ISSF Vice President

Grzegorz · Post by **Grzegorz** » Mon Oct 01, 2012 8:07 am

The answer given by Gary Anderson makes me sure that the rules should be more general, and afterthat interpreted by the Technical Committee.
Why?

...Barrel tuning and bedding systems have nothing to do with rifle movements before the shot ....

This sentence from the physical point of view is simply not true. It does influence on rifle movements. And the influence is quite important.

However, if one reads Gary Anderson explanation, knows well what is he speaking about. Because this is "the interpretation". Could you imagine to include so many "interpretations" to each new rule, in the ISSF Rule Book?

Sparks · Post by **Sparks** » Mon Oct 01, 2012 8:17 am

Grzegorz wrote:It does influence on rifle movements.

Not to be a smartass, but how?
Barrel tuners and bedding don't play any role until you get the barrel ringing by firing the shot, no?

taz · Post by **taz** » Mon Oct 01, 2012 8:28 am

When you increase the mass of a system you increase its inertia thus making the system withstand more to changes in its state.
On the other hand this is why you have maximum weights for rifles and pistols in the rules.

Sparks · Post by **Sparks** » Mon Oct 01, 2012 8:34 am

taz wrote:When you increase the mass of a system you increase its inertia

Ah, I see what you're talking about.
The whole active/passive thing seems to be the crux here again...

Grzegorz · Post by **Grzegorz** » Mon Oct 01, 2012 8:35 am

Sparks wrote:
Grzegorz wrote:It does influence on rifle movements.
Not to be a smartass, but how?
Barrel tuners and bedding don't play any role until you get the barrel ringing by firing the shot, no?

No. Just take your rifle without and with additional weights, close to the end, use the SCATT, observe movement of the trace, then extract raw data (time,x,y) of your 40 shots, apply Origin soft (for ex.) to make FFT analysis (Fast Fourier Transform - the tool to say something about vibrations) and the difference should be clear.
OK, you will observe changes of vibrations of the frequency about 1 Hz and some higher harmonics, whereas after the shot the frequency is - I guess - about 100 Hz. But this is still "vibration".

I have given this example ONLY to support my opinion: More general rules, and then interpretations. It is not possible to describe everything in the Rule Book.

Grzegorz · Post by **Grzegorz** » Mon Oct 01, 2012 8:44 am

Sparks wrote:...
The whole active/passive thing seems to be the crux here again...

Write "active", then interpret.
Why?
If I use gyro that works without additional external power source - is it active or passive? :-)

taz · Post by **taz** » Mon Oct 01, 2012 8:49 am

Any gyro is active.
Whether it is a simple mechanical one that you must use your own force to initiate rotation or an complex electronic one.
Your point is valid, the problem arises when you are shooting in a non WC event and the local uneducated judge interprets the rules...

Sparks · Post by **Sparks** » Mon Oct 01, 2012 8:57 am

Grzegorz wrote:
Sparks wrote:...
The whole active/passive thing seems to be the crux here again...
Write "active", then interpret.
Why?
If I use gyro that works without additional external power source - is it active or passive? :-)

It's passive. It's also magical, as no gyro can work without an external power source, even if it's only needed for a short time in the beginning to spin the gyro up :D

More seriously, Active and Passive have defined meanings in engineering, as I said earlier, so they're good terms to use here because there's no confusion over what they really mean - they were coined by engineers to talk specifically about this kind of distinction.