is it just my imagination?

[nonliberal]

Is it just my imagination or does it seem like wind effects some loads more than others? I don't mean changing to a bullet with higher BC or increasing the speed several hundred fps. It seems like after a minor fine tuning adjustment the bullet somtimes seems less effected by the wind than when the load was just a bit out of tune...

It doesn't make sense to me though since the wind should have the same effect on the bullet regaurdless of tune. Has anyone else had that. "I can't miss" feeling when the rifle is in perfect tune?

 

[Keith Glasscock]

I see that in my tuning sessions. I think it is a matter of the wind combining with a horizontal velocity component at launch. If you get lucky, the wind counters the velocity component, unfortunately, you were pointing upwind. Then the next one might have a zero horizontal component and get blown the correct amount downwind. There is always the chance that you get a component the opposite direction too, and it increases the wind effect.

Tony Boyer believes, according to his book, that one load can be more wind sensitive than another. I don't have any reason to contradict it, I just would like to understand it better. I've gone to testing in the wind in order to see what is going on. To say the least, I get groups that are perfect vertical (xx.5 grains of powder), and groups that are perfect horizontal (xx.7 grains of powder). I think I'm going to try that little spot (xx.6) between those two extremes and see if I can get a load that is good and wind resistant, but has good vertical. I'll know if it worked tomorrow - another testing session.

 

[Immike]

I think a good chamber is on the list also as well as the charge. It is hard to track down why one barrel shoots great and the next wants a new charge. I read article on a company that scanned the twist rates to show the variations throughout the barrel and saw alot of increases and decreases you wouldn't think they had.

 

[gunsandgunsmithing]

On this subject..I do most of the scoring at two different ranges where we hold matches. Doing so, I look at virtually every target. One thing that is clear, is that some guns or tunes in a given gun, consistantly make a smaller hole in the target that others. I believe this is a result of tune. Coincidently, those guns don't always win, but I do believe they are well tuned when the hole a single bullet makes is small relative to caliber. --Mike

 

[nonliberal]

Thanks guys! glad to see it's not just my imagination!!

 

[Turbulent Turtle]

I think it's your imagination.

But I'm certainly willing to read more of your observations.

 

[Immike]

Our local hall of famer at IBS short range bench would test barrels and sell the culled for a bargain, one was bought and set a world record. That will make you think!!!! The price went up on the barrels shortly after that. Every change you make changes everything. We are still learning this sport, Its best to be open minded. Rifle harmonics are high on my list.

 

[nonliberal]

Our local hall of famer at IBS short range bench would test barrels and sell the culled for a bargain, one was bought and set a world record. That will make you think!!!! The price went up on the barrels shortly after that. Every change you make changes everything. We are still learning this sport, Its best to be open minded. Rifle harmonics are high on my list.

I will probably see the shooter your are speaking of at this weekends VFS/ HBR match. Hope you can make it.

I'm a blank slate and try to learn something new with every outing.

 

[nonliberal]

On this subject..I do most of the scoring at two different ranges where we hold matches. Doing so, I look at virtually every target. One thing that is clear, is that some guns or tunes in a given gun, consistantly make a smaller hole in the target that others. I believe this is a result of tune. Coincidently, those guns don't always win, but I do believe they are well tuned when the hole a single bullet makes is small relative to caliber. --Mike

Very interesting, I have seen that as well but thought that was my imagination also.
Do you think this is an indication that there are different degrees of stability?
That would indicate there is more than just picking a twist that will stabilize a certain bullet if it can still allow micro oscillations that effect accuracy.
Or do you think its harmonics too where you have to hit a true dead spot in barrel vibrations so its not imparting yaw on the rear of the bullet as it leaves the barrel?

I could see where these oscillations would grab the wind and be way more sensitive than a bullet thats flying solid.

 

[gunsandgunsmithing]

On this subject..I do most of the scoring at two different ranges where we hold matches. Doing so, I look at virtually every target. One thing that is clear, is that some guns or tunes in a given gun, consistantly make a smaller hole in the target that others. I believe this is a result of tune. Coincidently, those guns don't always win, but I do believe they are well tuned when the hole a single bullet makes is small relative to caliber. --Mike

Very interesting, I have seen that as well but thought that was my imagination also.
Do you think this is an indication that there are different degrees of stability?
That would indicate there is more than just picking a twist that will stabilize a certain bullet if it can still allow micro oscillations that effect accuracy.
Or do you think its harmonics too where you have to hit a true dead spot in barrel vibrations so its not imparting yaw on the rear of the bullet as it leaves the barrel?

I could see where these oscillations would grab the wind and be way more sensitive than a bullet thats flying solid.

The only honest answer I can give about this phenonena is that I simply don't know why. I would lean more toward harmonics because I've seen it come and go from the same bullet/barrel combinations. I THINK it's tune related.
It's difficult to test for it, because of variables like humidity that will affect the paper, hence the hole size. But side by side, comparing several guns on the line at the same time, it's real. I've heard of some shooters tuning for small holes for quite a while, but it just seems like with the variables that have to be dealt with, it'd be a very fortunate tune. I've found it before, but I think it was luck, because, while the gun seems to shoot very well, I can't seem to find small hole size with any consistency.