TargetTalk

I hate to disagree with my friend Stale, ( glad to see you posting again BTW) but if you have a pistol or pistols shooting that big a group, something is wrong with the gun. However, as noted even those huge groups are still 10s. I have been testing airguns for the military since the late 80s and as as businessman for the last 8 years and would guess that there are several hundred airpistols from Model 65s to state of the art and I can recall four or five that shoot less than a one hole group, and a distinct problem such as ruined crown, rusty barrel or malfunctiong regulator was the culprit.

Factory testing---- all of them have several lots and sizes on hand. If they first one they pick up shoots a good group, thats what gets marked. If not, they get a second batch and shoot it, if it works, then it gets written on the test target. or the move on to the next. but if after four or five attempts and their is not decent group, you can bet they will be looking to see what is wrong with the gun. Smallbore is a bit more tricky, and maybe go through 10 different lots but the same basic rules apply

oh and hate to see people bring up the what if I shoot a 10 (sight picture) and get an 8 because of ammo variance. Odds are equally in your favor if you shoot an 8 sight picture that you get a 10.

Nice reply! You were the best reply!
The 4.5mm are much tighter in the LP 1 so I really thought they tested it with the 4.48mm for a reason ,maybe because the barrel was smaller for some reason (custom?).It didn't make sence but I thought I'd ask it.Usually barrels are all made the same way. All my guns came with test targets that used 4.5mm so I really thought that that's all they used to do the test targets.

Darticus,
A few observations if I may.

1/ I've never known of a technically minded person who refused to do a simple test to prove or disprove a theory.

2/ Never heard of an example where scaling from 4.48 - 4.50 made an object unstable in flight.

3/ Giving apples to the teacher doesn't gain respect from your school friends.

Lets be honest , we do enjoy little mini R&D projects , we all like to tinker . The will o the wisp is to find the magic combination , and get a magic increment for nothing . Personally , the only time I have been able to discern any difference , was between different weights ie: match rifle as opposed to match pistol pellets .

All that said , trying different stuff is fun .

Chris

BJ wrote:Darticus,
A few observations if I may.

1/ I've never known of a technically minded person who refused to do a simple test to prove or disprove a theory.

2/ Never heard of an example where scaling from 4.48 - 4.50 made an object unstable in flight.

3/ Giving apples to the teacher doesn't gain respect from your school
friends.

1/ Think this is a simple test? - prove a larger heavier pellet 4.5mm could be more or less stable than a 4.48mm pellet. We are talking mass and volume difference.Big truck little truck? Think about the test!

2/ Apparently not a good physics mind here.Try a fat mosquito flying!

3/ Someone explain! Did I lose respect from my friends here? Not sure! Glade your a guest!

darticus , you have posed a wide array of questions , which cover the whole gammit . I dont see you getting two pages of response if it was an elementally dumb question . Lets be honest playing with chronys , different pellets etc , while solemly pretending we know what we are doing is lots of fun. It's kinda like high school physics labs shoulds have been .

Chris

Really didn't think this was a real problem question.
If you knew the answer you would reply if not you wouldn't reply.Really not that important but some shooers are very technical and might have thoughts about this.

Just thought someone may know the answer. Maybe the people that use heavy pellets or light pellets already know the answer and why.

Well, for starters, look at the easily available information about match pellets. There is no correlation between head size and pellet weight, as you have been assuming throughout this thread. A 4.50mm head diameter pellet is not, per se, heavier than a 4.48mm head diameter pellet. And if you are talking about external ballistics, the 0.02mm difference in head size between pellets of equal weight, is insignificant at short distances like 10M. A little bit of home work could have told you that, and saved this whole thread.

FredB

darticus wrote:Really didn't think this was a real problem question.
If you knew the answer you would reply if not you wouldn't reply.Really not that important but some shooers are very technical and might have thoughts about this.

Just thought someone may know the answer. Maybe the people that use heavy pellets or light pellets already know the answer and why.

You really seem to make this 10x more complicated than it is and aren't actually reading the answers you have been give - see Richards post

"Here you go 4.48 is not more accurate than 4.49 or 4.50 or 4.51. Accuracy is not acheived by the pellet alone."

Different individual guns perform better with a specific size pellet. It's in part due to the minute variations in internal diameter of the barrel. There is only one way to find out what your gun favours and that's to test them all and see. From a practical perspective the size tested in the gun should be pretty much perfect so you won't go too far wrong with that size.

Rob.

GREAT REPLYS.Thanks

darticus wrote:

BJ wrote: 2/ Never heard of an example where scaling from 4.48 - 4.50 made an object unstable in flight.

2/ Apparently not a good physics mind here.Try a fat mosquito flying!

I would have thought a good physics mind would be able to differentiate between something scaled up and something fatter.

In the same situation (162EI fixed,10 shoots) test RWS R10 4.49mm 0.5g ,
H&N final match 4.49mm 0.5g , JSB 4.49mm 0.475g (in fact I test from
0.470g to 0.479g , 10 kinds of weight) , RWS R10 4.5mm 0.53g , I have
the result , the JSB 4.49mm 0.471g has a hole less then 4.7mm , RWS
R10 4.5mm 0.53g has a hole like a flower (more then 10mm).

I think , if I get the pellet with bad test group , it will let me more bad
group when I shoot target .

But I don't think the bad group pellete will let you from 10 to 8 .

When I Received my Steyr LP 10 it had a test card using 4.49mm and I could only make out 2 shots on the card.

I contacted Steyr and they informed me that; they the test sizes for 4.48 up and that my pistol shot best using 4.49mm. They also told all their test cards are 5 shots. They would _not_ tell me make of pellet they use, nor would thy advise me on a particular brand.

Since these are the result of actual tests “sung” fit does not appear to be relevant.

I agree with pilkguns you cant out shoot the gun, however the test is not so much about how accurate the gun is but how consistently pellet flies once it has left the barrel. There are many factors involved the individual barrel, the pressure setting, pellet size and weight.. There are people who, after selecting the best pellet make and size, then proceed to adjust the pressure in 1 fps increments whilst checking group size as 20 yds.

All this testing does not make you a better shot. But sport psychologists will tell you confidence is a big factor and will make you a better shot. Having the utmost confidence in you equipment helps the mental game. This is probably the biggest reason for doing the tests. Testing only takes a couple of hours which leaves you the rest of the year to practice and compete in confidence.

Personally I have not done pressure testing, however I have tested the difference between RWS R10 and HN Final Match at 14meters. The interesting thing was that the R10s cut neater holes but the Final Match group was tighter but only by about 1mm if that ( would less at 10m). Not much, but in a final where points are score in tenths I like to have that edge.

Lastly there is the saying; “practice hard, compete easy”. Practice shots are a very important, perhaps more important that competition shots. It is your practice shots that provide you with feedback and enable you to improve. I value them which is why I use match pellets in training. Besides I spent around $1500 on my gun so I am not going to put junk down the spout.

Best regards

SD

Well, I'm certain H+N is glad to have you as their customer. I for myself stick to Ragnar Skanaker's advice about FP ammo...

Tycho wrote:Well, I'm certain H+N is glad to have you as their customer. I for myself stick to Ragnar Skanaker's advice about FP ammo...

And what was that ?

streamdreams wrote:When I Received my Steyr LP 10 it had a test card using 4.49mm and I could only make out 2 shots on the card.

I contacted Steyr and they informed me that; they the test sizes for 4.48 up and that my pistol shot best using 4.49mm. They also told all their test cards are 5 shots. They would _not_ tell me make of pellet they use, nor would thy advise me on a particular brand.


SD

That's odd I have 3 Steyr's and the test target for each clearly states 4,5 RWS, 4,5 RWS and 4.49 RWS. So it would seem that they are using RWS, it doesn't look like a secret.

streamdreams wrote:

Tycho wrote:Well, I'm certain H+N is glad to have you as their customer. I for myself stick to Ragnar Skanaker's advice about FP ammo...

And what was that ?

If I remember correctly it was something like use cheap stuff. Pretty rubbish advice if you ask me, and I don't care who said it - it doesn't make it any more meaningful or technically correct.

Rob.

I once tested a Morini 162EI, 10 shots at 10meters and with quality pellets, in my case H&N finale match Hi speed and green Jsb match, it shot groups with a vertical spread of 1,5 mm and no measurable horizontal spread.

However when I tested some pellets that was made available through something called "team Skanåker", at a low price, things looked a bit different...
A symmetrical grouping with a c-c spread of 9 mm...
"Lapua sportsman" ribbed pellets, hmm...

I´m with our host on this one, use any quality pellet and be happy with it

Btw I have heard that Ragnar used to weigh his match ammo (for FP) and sort it accordingly, so his advice to use cheap stuff perhaps applies to training ammo...

/Anders

I love these threads!

Like eating cotton candy or watching American television . . .

Anyhow, a few things to consider:

1) Error in the system is mainly "additive" ie gun error is added to human error to create total error (in how far the center of the hole in paper lands away from the center of the target on any given shot). So technically any source of error just makes things worse- it's a matter of "how much worse" you are willing to accept

however

2) as to random error canceling out ("just as likely to land the pellet closer to as farther from the center") actually that is pretty much true. Except that it's false. Geometrically, perfectly random error would land the hole the same distance about 1% of the time, closer about 49% of the time, and farther away about 50% of the time. So see point number 1 above. Error is Bad.

But then again

3) Modern match grade pellets *all* have very good characteristics, and the differences seen are mainly from the interaction between a particular pellet and the gun (barrel, pressure, etc). At the edge of performance (very good pellets) the variation you get between brands is less than the variation you get between lot numbers. And the variation from sizes/weights is somewhere in between. But the variation from any source (Brand, Size, Lot) is pretty much negligable. Compared to the variation contributed by the shooter.

And

4) any 5, 10, 15, or 30 shot group testing will be absolutely meaningless. IF you follow statistically rigorous laboratory testing procedures, yoiu will find that while any given comparison of 5, 10 etc. sized individual trials will "demonstrate" that A is better than B," for another set the reverse will be true. It takes an awful lot of testing to detect the true underlying differences between pellets. These true differences are actually quite subtle. At the end of the day, when you fire enough rounds to achieve statistically significant results, you find the the differences are practically insignificant.

So

5) Pick something and train. It's called "Process Variability Reduction." Tackle the main source of error: where the muzzle is pointed when the pellet leaves.


Hey, let's talk about electronic vs. mechanical triggers again . . . !

Steve Swartz

Steve Swartz wrote:I love these threads!

[snip]

5) Pick something and train. It's called "Process Variability Reduction." Tackle the main source of error: where the muzzle is pointed when the pellet leaves.

Steve Swartz

absolutely spot on [again] :)