Wind deflection differences: diabolo pellets V's "bullets

[greyskull]

Some comments further to the topic of wind deflection of diabolo pellets:

Rob Farnsworth, a top FT shooter in the UK had this to say after a very windy GP FT shoot.

Red face Humble pie... and the wind...
Grief, it's hard to type this thread starter....

For years I have denied that pellets move up and down in the breeze... because there's been very good more likely reasons why that should happen when i've seen it happen...but after yesterday I am willing to admit they might move... still not convinced they may move as much as some thing, or that it's the sole reason that people shoot high or low, which I think is largely range/shift driven.

Yesterday we had a strong breeze coming right down the throat of South Dorset's plinking range. When it swung left it took 6" off me at 55yds, which in my book puts it about 20 mph... it was strong enough that the windy was horizontal and could buffet you a tad.

We started shooting at 55, and had good consistent groupings, pellet on pellet at 55, but now and then the shots would fly 1/2 MOA up, or 1/2 MOA down... and group there. In the end, I elected to only shoot when the wind was soft and consistent and the shots stayed level. Looking at the trend, left was lower by about 1-2 clicks, right higher by 1-2, mostly both in the 1 click range. Off the bench it meant that I was less likely the weak link.

What sort of nailed it for me was that even though my windy was pointing strong left, a lot of shots would go straight, but low... but when the windy was pointing straight down, they would go straight but be on the level... there weren't many taken when it was pointing right that went straight, but they did climb a click.

Shots that went left when the windy pointed left didn't drop as much as those that were fired when the windy pointed left but went straight. The groups I was getting were tight, but just seperated by 1/2 MOA. Only when I shot in consistent wind did I get a consistent group.

The feeling was that when shots are going left, they may go a little low, and that when they go right, they may go a little high... but we are only talking 1/4 MOA... but the real damage seemed to be when a really strong wind pushed them back on central line.

So I think that perhaps when the wind is super strong, you may see some lift and drop depending on what it's doing, but we are talking very strong wind, and still marginal amounts, and I still reckon on most occasions it's going to be down to rangefinding or shift errors, and you need to dial out pellets first.

Need to investigate more, and stick a chrono at 55 on a windless day and see what happens then for a comparison... couldn't be arsed to stick the chrono out yesterday as I lacked the tripod... and besides, the occasional horizontal drift would have been well enough to clip the sensors...

Chairgun says it should happen, but not to the same degree... but then it says that about a lot of things, and i've found it's findings to be right in direction, but less than what seems to happen in the real world.

What would be great is to be able to get two CED M2 IR's together one day, tie them so they are reading the same and do some BC work as well, cos I have a new theory as to why sizing might reduce vertical spread on pellets.
__________________
BFTA/NSRA County Coach
EFTA Secretary
Chairman: Parkstone Gun Club

cheers
GS

[Yrrah]

Some comments further to the topic of wind deflection of diabolo pellets:

Rob Farnsworth, a top FT shooter in the UK had this to say after a very windy GP FT shoot.

Red face Humble pie... and the wind...
Grief, it's hard to type this thread starter....

For years I have denied that pellets move up and down in the breeze... because there's been very good more likely reasons why that should happen when i've seen it happen...but after yesterday I am willing to admit they might move... still not convinced they may move as much as some thing, or that it's the sole reason that people shoot high or low, which I think is largely range/shift driven.

Yesterday we had a strong breeze coming right down the throat of South Dorset's plinking range. When it swung left it took 6" off me at 55yds, which in my book puts it about 20 mph... it was strong enough that the windy was horizontal and could buffet you a tad.

We started shooting at 55, and had good consistent groupings, pellet on pellet at 55, but now and then the shots would fly 1/2 MOA up, or 1/2 MOA down... and group there. In the end, I elected to only shoot when the wind was soft and consistent and the shots stayed level. Looking at the trend, left was lower by about 1-2 clicks, right higher by 1-2, mostly both in the 1 click range. Off the bench it meant that I was less likely the weak link.

What sort of nailed it for me was that even though my windy was pointing strong left, a lot of shots would go straight, but low... but when the windy was pointing straight down, they would go straight but be on the level... there weren't many taken when it was pointing right that went straight, but they did climb a click.

Shots that went left when the windy pointed left didn't drop as much as those that were fired when the windy pointed left but went straight. The groups I was getting were tight, but just seperated by 1/2 MOA. Only when I shot in consistent wind did I get a consistent group.

The feeling was that when shots are going left, they may go a little low, and that when they go right, they may go a little high... but we are only talking 1/4 MOA... but the real damage seemed to be when a really strong wind pushed them back on central line.

So I think that perhaps when the wind is super strong, you may see some lift and drop depending on what it's doing, but we are talking very strong wind, and still marginal amounts, and I still reckon on most occasions it's going to be down to rangefinding or shift errors, and you need to dial out pellets first.

Need to investigate more, and stick a chrono at 55 on a windless day and see what happens then for a comparison... couldn't be arsed to stick the chrono out yesterday as I lacked the tripod... and besides, the occasional horizontal drift would have been well enough to clip the sensors...

Chairgun says it should happen, but not to the same degree... but then it says that about a lot of things, and i've found it's findings to be right in direction, but less than what seems to happen in the real world.

What would be great is to be able to get two CED M2 IR's together one day, tie them so they are reading the same and do some BC work as well, cos I have a new theory as to why sizing might reduce vertical spread on pellets.
__________________
BFTA/NSRA County Coach
EFTA Secretary
Chairman: Parkstone Gun Club

cheers
GS

Well if I read him correctly, he has discovered what I had reported which is opposite to conventional rimfire bullet wisdom.

If you are in touch with the gentleman you are welcome to reference my report to him with the date. But I first reported the phenomenon some years ago and I must say that, apart from one experienced older shooter in Oregon, my earlier report did not go down too well with those who were just locked in to powder burner mentality.

Thanks for taking time to follow up with this reference reference for me. ... Best regards, Harry.