[K Soze]

I posted here a while back that I was having problems with my 93R17 BVSS
http://www.rimfirecentral.com/forums/showthread.php?t=391394&highlight=k+soze

It seems to be fine now. Although I do get more consistent groups with the 93 BRJ .22 WMR. I shot the best groups I have with both guns today. 83 degrees 60 percent humidity and a 3 MPH wind. The one group with the .17 was so good I checked the plywood board the target was on to make sure I did not miss the paper

I like the stock better on the BRJ better, I think that might account for the consistency difference.

Please excuse the crappy cell phone pic. I threw the targets out then thought better of it and tore off the two good groups for further reference. They are both 5 shot groups at 100 yards.

 

[DKSAC2]

Great shooting. The wind can sure cause the groups to open.
I shot my best group ever when the wind was as you are describing with a 22 LR.

Keep after it, you are doing great and it looks like you have a great rifle. I also have a BRJ and think it's one of the best stocks Savage makes.

My Best, John K

 

[tuj]

Even 10mph winds don't affect the 17HMR that much.

There's were shot in some mild wind that started and stopped a lot.

 

[DKSAC2]

A lot depends on how far you are shooting, wind gusts, wind can be blowing in several different directions between you and the target.
While drift tables can be helpful, sometimes the real world is much different than a chart.
As you can see, your groups have some horizontal movement, most likely caused by the shifting winds.
I'm still working on my wind doping skills, there are not a lot of shooters who are really good at reading the wind, it's darn hard to do.
The wind still trips me up more than I would like.

John K

 

[HOG55]

17 HMR little to no ricochet. I've shot ground squirrels with a partner shooting a .22 mag. No comparison. the .17 HMR is much safer.

 

[K Soze]

Interesting graph. I don't understand the relatively large wind drift delta between the 33 grain .22 and the 40 grain .22

 

[DKSAC2]

Bullet shape and weight. The lighter bullets have shorter flight time, which can be a help, but get pushed around by the wind easier.

John K

 

[K Soze]

If you look at the chart the two .22 mags are only 100 fps different, yet the lighter bullet is much less prone to wind. How is something the same shape and less weight less prone to wind deviation? What am I missing? Is that 100 feet that much of a difference?

 

[gmd1950]

Ballistic co-efficient, a not always apparent but always there factor. .114 vs .127 is a very large difference. BC and velocity have much more to do with all this than bullet weight, though some seem stuck on the notion that a light bullet is helpless in a crosswind, merely displays their lack of understanding.

 

[K Soze]

So you are sayying I don't understand? Ok you got me. I don't completely indersand...... That is why I asked, thanks for kind of answering.

I will go google BC now.

 

[nodak]

Higher BC means it slips through the air better and in turn is less effected by wind and air resistance. Hope that helps.

 

[K Soze]

Thanks. I get the basics I am just surprised that the heavier projectile moves more with a small difference in speed

 

[gmd1950]

The remark was aimed at an earlier poster who claims to be someone who should show a far better understanding of ballistics and shooting in general than he does, no offense meant to anyone.

 

[Provincial]

Exposure to crosswind

One thing I learned in my commercial flying days is that a slower plane is affected by a crosswind more than a faster one., regardless of how large or heavy the plane is. This is because the slower plane is exposed to the crosswind for more time.

In this case, the body in motion (the airplane) is completely immursed (propulsion, etc.) in the moving air. The bullet gets it's initial propulsion outside of the moving air, but once it leaves the barrel it becomes affected by the wind. After it leaves the barrel, forward momentum is the only thing resisting the wind drift.

The heavier bullet takes longer to get to the target, hence it is exposed to the crosswind for a longer time, however minute. :AR15firin

 

[K Soze]

My engineering intuition would have told me other wise because of the momentum of the the object with more mass, but I did a little research and it all agrees with the above graph.

Another nice day here and I will be heading out to break in my new MK II BSEV, the savage rimfire bug bit me hard.

 

[DKSAC2]

Ballistic co-efficient, a not always apparent but always there factor. .114 vs .127 is a very large difference. BC and velocity have much more to do with all this than bullet weight, though some seem stuck on the notion that a light bullet is helpless in a crosswind, merely displays their lack of understanding.

Most people I know tend to shoot the .17 far longer distances than the 22 cal. In that case, the .17 has a reputation for being pushed by the wind more due to the longer range.
Take the 2 bullets and shoot thenm at 100 yds and the .17 will have less wind drift.

Another factor comes into play with the regular velocity 22 caliber when it goes supersonic to sub sonic. The 22 RF is about the only round with this problem at ranges of about 100yds, maybe less.

So I'm talking what happens in the real world, not on a graff. Most people I know that hunt with the .17 like the distance, 150 yards being common, most who shoot the 22 do not shoot that far.

In a purly technical sence, you are correct, but in the real world, most people tend to go for longer shots with the .17 which has given it a rep for wind drift.

Oh, quick, I think someone said something bad about a CZ, better go check

John K

 

[gmd1950]

Replies like that just make my point John.