Questions On Checking Power Level?

P

Paul Bendix

Guest
I have been setting my power level with the pellets and lube that I find shoots best in my airguns. The same weight pellet in JSB and CP can have over 100 fps speed difference. I read that you had to provide the pellets that you wanted to use and they tested your gun with the pellets. They sealed your pellets and those are the ones you shoot with.
Now I see this.

All,


The latest from Carl Boswell.


So it would be as follows - now .22 is in the field - (sorry no one uses .22 in Europe except for hunting)


Air Rifle Power Check Procedure

Air Rifle power to be checked before the match so there should be a suitable chronograph system available at each event. Common Handler & Natermann sport pellets or similar to be used. A sequence of 5 shot to be measured by a chronograph. As “effective power” will be considered the speed media value (converted in joule) noticed by the tool. Air Cylinders to be filled at maximum charge before test.



Note: J = • m Vo2 Where m is expressed in Kg, Vo speed in meters per second.




To verify the real power of the 16.27 Joules (12 ft/lbs) or 27.12 Joules (20 ft/lbs) maximum Air Rifles a;


.177 Match Pellet of 4.50 in diameter and 10.65 grain in weight must be used


= max velocity of 712.5 and energy of 12 ft lbs

= max velocity of 919.5 and energy of 20 ft lbs




.22 Match Pellet of 5.51 in diameter and 21.14 grain in weight must be used


= max velocity of 505.5 and energy of 12 ft lbs

= max velocity of 652.5 and energy of 20 ft lbs




I am going to get the pellets Carl has specified. Thanks,




Steve George








--------------------------------------------------------------------------------
From: STEPHEN GEORGE <georgestephen@bellsouth.net>



All,


This what I received from Carl Boswell.


Yes people can retest


Air Rifle Power Check Procedure

Air Rifle power to be checked before the match so there should be a suitable chronograph system available at each event. Common Handler & Natermann sport pellets or similar to be used. A sequence of 5 shot to be measured by a chronograph. As “effective power” will be considered the speed media value (converted in joule) noticed by the tool. Air Cylinders to be filled at maximum charge before test.



Note: J = • m Vo2 Where m is expressed in Kg, Vo speed in meters per second.

To verify the real power of the 8.25 Joules or 6 ft lbs maximum Air Rifles a Match Pellet of 4.50 in diameter and 0.53g in weight must be used.

To verify the real power of the 16.27 Joules (12 ft/lbs) or 27.12 Joules (20 ft/lbs) maximum Air Rifles a Match Pellet of 4.50 in diameter and 0.68g in weight must be used.



Thanks,


Steve George


What does this mean? If my gun shoots the test pellet at under 20 fpe and at that setting the pellets I will use my gun shoots at 23 fpe it's OK????

My 20 fpe gun is a .20 cal what pellets do I test with???

Paul
 
Paul,

First, the .20 caliber question has been asked. There will be a standard pellet to test power levels in .20 caliber air rifles, have no fear.

As to any differences there may be between the test pellet and your preferred pellet, my suggestion is to buy a tin of the test pellets and see what power level they produce. The test procedure prior to the match will determine whether your air rifle is under the prescribed power level for that class. This may not be perfect but we have to play by the rules.
 
what is the reasoning behind the .450mm dia.restriction? does this mean that dia. in excess such as 451 or 452 ect. are not legal? I just looked at the label on my tin of h + n sport .69g,.452 dia, jsb exact heavy .670g no size listed on tin, and so according to above neither are acceptable? Nice way to kill participation, maybe that's the plan.
 
I'm working on it!

I remember reading the exact same thing as Paul about us supplying the pellets.

DanB brought up the point of how using a pellet with a different lube, or, worse yet, no lube at all would not only create havoc in the barrel environment that has been created by each competitor, but would also produce different results than those found while setting the gun up in the first place while using the chosen pellet/lube combination that will be used during the competition.

It is wrong to think that by using an unlubed pellet to run these test would do little if any harm to the hundreds of hours spent getting everything prepared in balance, and that all that would be necessary to only give the bore a good cleaning once the testing has been done to return things to where they were. Not so!!! After any type of bore cleaning it takes 2 to 300 shot to properly settle down and reseason the bore to the levels of where it was at prior to the cleaning. I know that I for one would much rather bring along 20 or so extra pellets for the Officials to use for their purposes than to have to bring along, and then waste, another 300 pellets in order to reseason my bore because of something that could have been avoided in the first place.

If we want to field the best possible teams, from all over the World, and see the optimum level of results, we need to take into consideration the time spent by each and every competitor in attendance while preparing for the Worlds.

Let's use the designated pellet supplied by the competitor, not the system. And, if that's not already part of the system, then the system needs to be changed ...for the better. But, as Paul said, I think it's already part of the rules.

Dave Shattuck
 
Just as a heads-up, the correct answer to all of this, and what Paul and I were referring to, can be found on pages 15 and 16 of the "OFFICIAL" WRABF RULE BOOK as published on their website. There it states how the competitor is responsible for supplying everything, other than the measuring devises, needed to do any testing, then once tested the box/tin of pellets is to be sealed and remain so until when the competition begins, plus will need to be resealed if there is any prolonged interruption during the competition. You can read it for yourself and make your own interpretations.

Dave Shattuck
 
Yes that is How I took also, but that does not seem to be the case as posted at the beginning of this thread " 177 pellet of .450 dia at .68g must be used" add in the sealed container from the rule book and you are not using what you have found to optimum in your unit. Maybe I am reading too much into this or perhaps there is a breakdown in some sort of translation. Additionally there are variances in the chorno units themselves. and how it is placed in relation to the muzzle. I have no problem with verifying a power level with a competitors pill of choice, but I take exception to a dictated pellet which may throw a wrench in the works for some. As Dave stated there can be a significant velocity change between pellets, enough so that it could cause a rejection for a particular class.
 
Similar

Dos not the or similar open it up to most pellets ?
 
Boy o Boy -old Larry Brown would have loved this..lol.H.B.
 
"Common Handler & Natermann sport pellets or similar to be used."

It seems folks are getting worked up over nothing.

Most pellets are SIMILAR .

Takecare Kevin
 
Taken from the Rules.

E.8.9 Air Rifle Power Check Procedure 1) 10 of the competitor’s pellets to be weighed and the average noted.
2) A string of 10 shots over using a chronograph, an average velocity would be calculated.
3) The power output would be derived from the information in 1 and 2, buy using the following formula;

Kinetic energy = weight (grains) x speed (ft/sec) x speed (ft/sec) 450240 This is then multiplied by 1.356 to attain the correct Joule value 4) If the power is within the prescribed limit the rifle and pellet box/tin will be labelled as such, the
pellet box/tin being sealed with the label until the match starts then re-sealed after each detail.
5) If the power is outside the limit time would be given to sort the problem before a re-test.
6) Competitors should make sure there are sufficient pellets in the batch that have been tested to
shoot the whole match as additional testing will not be done unless unforeseen circumstances make
such a test necessary.

I have no problem with the rules as written.

I must be doing something wrong! Out of a 500 pellet in a tin your lucky to get 40 percent of SIMILAR pellets.

Now tell me with a specific weight of 10.65 grains and I shoot a 7.8 grain how that is SIMILAR?

Hope to see everyone this Summer in SC.

Paul
 
Boy H.B., do I ever agree with you about Ol' Larry Brown loving this one. I never met the man, but I did follow his rants about rimfires. Sometimes I agreed with them, and sometimes I didn't, but we both knew exactly where the other stood at all times because it was all kept above board and out in the open.

Kevin, the problem all started with my, as well as several other match directors, receiving an email about how things were to be done the day before the Worlds. But what the email said wasn't how it is described in "The Rule Book". If you read the first posting, that was pretty much what was in the email, and that was being taken literally, where in the Rule book it specifically states that you use 10 pellets provided by the competitor and taken from the tin/box that said competitor is planning to use during the match. First you determine the average weight, then you shoot those 10 pellets across a chronograph to determine the average velocity, which now gives you the needed information to determine the average ft/pds of energy. That is what it says "in the Book".

Since people will be traveling in from afar they need to know exactly what to expect before arriving. In a case where you have people coming in from such a wide array of locations, you need one set of hard and fast guidelines to go by. That way everybody will know exactly what to expect before hand, and if they don't, it's their own fault.

I say what follows from experience: If there are any discrepancies before things even get started, you had better believe that some shooters will take things to the limit. And then, because of having already gone against the one reference manual that tells the way it's suppose to be, we will have nothing left to fall back upon as "The Book" will have already been made null and void by this one action. I hate to be a stickler, but if I have any say in this we are going to go exactly "by The Book" before, during and after the match. Then if any question arises, or if anything is challenged, we can pick up the Rule Book, read what it says, make a determination, and nobody can argue the fact after that. It will be a done deal, plain and simple!

Dave
 
Dave you got that right-Larry been gone about 9 years but his thoughts go on -in others..loveing it. H.B.
 
got to be the rule book controls, right ?? the letter of mr george is an example...

or is he or some other originator of the correspondence a rule maker, etc >
I just want the people on our United States team to not be hindered by last minute stressors or snafu's ...
dk
 
The Rules

Yes, rule E.8.9 is out there in black and white. More experienced people than I tell me that weighing air rifles and 10 pellets, doing the math and shooting those 10 pellets over a chronograph could take 10 minutes per competitor. When you have 5 shooters at a match, no big deal. If you have 60, some with 2 air rifles, it becomes a long day.

A standardized pellet, in each caliber, makes weighing pellets unnecessary. A 5 shot string is also faster. Hopefully, 3 minutes per competitor. If you have 60 competitors, it makes things much more comfortable.

The standardized pellets can be acquired prior to the match and competitors can see for themselves what and how their air rifles perform across a chronograph. Yes, there will be differences, yes, your air rifle might test under the legal limit with the standardized pellet and then shoot with more power with your preferred pellet and lube and yes, there may be other flaws I have neglected to mention.

Still don't like it, build your own sandbox and play by whatever rules you like.
 
One simple question. When shooting for score, which pellets am I allowed to use? The one I brought along or this "standardized pellet" ? ok ok 2 questions
 
Easy Answer

After shooting the standardized pellets to determine if your air rifle in within the fpe power level rules, you shoot the pellets you "brought along" on the record targets.
 
I do believe we need to find the lid for this can of worms. If the US teams have to use their pellets these pellets should be available in the US for the shooters to tune their guns.
MHO
Larry B
 
Pellets

Larry,

Most of the big dealers in US carry these pellets. Pyramid/Airguns of Az/Precision etc.
 
Do I have this right ? I need to set my 12ft.lb and my 20 ft.lb .177 rifles up with H/N Baracuda ( only 10.65gr. pellet ) . Then I shoot what ever shoots best for me no mater what the ft. lb. they end up. Thank You
 
That is correct, my rifle picked up 30fps, just checked a .177 that gentleman picked up 30 fps in his rifle, and that's both being on the safe side. Haven't shot for score yet, both show better consistency on the chrony also. If your shooting a pellet as of now in the sub 12 or 20, there method could be a plus. I wouldn't fight it. It is what it is.

Joe
 
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