accuracy at 100 yards

[ifldned]

How accurate must my rifle be at 100 yards to shoot 2 inch groups at 300 yards using 32 grain bullets at around 4000 fps?
ifldned

[VLSS]

How I understand it is you add for every 100 yrds. So if it groups .5 at 100, 200 will be 1 and 300 will be 1.5. Now this is in a perfect world so in real world circumstances this prolly isnt gonna be 100% true. So your gonna want .5 to .75 groups at 100

[Fred_C_Dobbs]

Presuming you can hold your PoA as accurately at 300 as at 100, 2/3rds".

[ifldned]

I think we have to factor in the BC of the bullet. That said, 1 moa at 100 yards does not equate into 3 moa at 300 yards. I shoot match 22lr rifles and a rifle that groups .2 inches at 50 yards will not group .8 inches at 200 yards which is 4x the distance. If I had to guess at what it takes to get 2 inch groups with a .204 at 300 yards I'm thinking sub quarter inch groups at 100 yards in excellent wind conditions.
ifldned

[jo191145]

Breeze, wind, breeze, wind, Got flags?

All depends what you mean. Do you want to shoot one 2" group occasionally?
Or do you want to put fifty rds in a 2" circle? Big difference.
All comes down to what the wind is doing that day and your ability to cope.

Last IBS match I shot we were seeing at least 6" of horizontal at 200yds if you pulled the trigger during a switch.
We coined it "National Flag Day"

[Fred_C_Dobbs]

BC per se has no effect on accuracy.

[ifldned]

jo191145,
Congrats on your shooting accomplishments. Yes, I use wind flags,anemometer, laser rangefinder and binoculars. I post the flags at about 4-5 squirrel mound areas and when I set up I use one at my rifle station. Then, I make rounds during the day rotating from one shooting site to the next giving the squirrels time to come up again. I'm shooting in central California. These squirrels see really good and after being shot at a few times I'm only getting head shots and half body shots at 150-200 yards with a 22lr. I'm using two benchrest rifles, a 54 Anshutz and a 52 custom Winchester. I'd like to reach out to 300 yards as my friend with the walnut and almond orchards wants these critters gone. Personally, I'm a paper shooter and don't care if I hit them that much, 200 yards is a good shot for a 22lr. I'd like to get a rifle that averages 2.5 inch at 300 yards with frangible bullets without having to have a custom rifle built and the .204 looks like a good round as I want to see the impact. ifldned

Fred,
I think B.C. of bullet does matter. Different bullet configurations shot at same velocity will buck the wind better depending on their B.C. ifldned

[jo191145]

200yds with any rimfire is better than good

I think you'll like the 204.
If you got the cash a Cooper is always a good choice.
Only factory guns I've ever owned are Savage.
Think the factory barrel is not up to snuff? Loosen the barrel nut and screw on a prefit Shilen for $300
I've had good luck with the factory stainless tubes.

Only downside is the BC of the frangible bullets you need to use.
I've tried the 26gn Barnes. Sure makes the chrono work in numbers its not used too.
Top accuracy node was 4650 for me anyway.
They slow down real fast though. Like shootin feathers out of a straw
There are new frangibles either on the market or coming soon. 32's I believe.

I quess we should both ask the question. Are these new 32gn frangibles designed appropriately for a standard 12 twist?

[Fred_C_Dobbs]

Fred,
I think B.C. of bullet does matter. Different bullet configurations shot at same velocity will buck the wind better depending on their B.C. ifldned

You're talking apples and oranges. Doping the wind is the shooter's responsibility, not the bullet's. Provided the shooter does his part, a bullet that shoots 1" @100 yards will shoot 3" @300. And BC is not directly connected to bucking the wind.

[rayfromtx]

Fred,
I think B.C. of bullet does matter. Different bullet configurations shot at same velocity will buck the wind better depending on their B.C. ifldned

You're talking apples and oranges. Doping the wind is the shooter's responsibility, not the bullet's. Provided the shooter does his part, a bullet that shoots 1" @100 yards will shoot 3" @300. And BC is not directly connected to bucking the wind.

That is what would happen in a perfect world. In the world we shoot in, a ten mile per hour wind that is unaccounted for will cause the bullet to miss it's mark by .9" at 100 and 3.3" at 200.(this of course is representative of what we shoot and varies widely due to a number of factors) BC is directly connected to performance in wind because wind drift is directly related to the loss of velocity of the projectile. If the bullet did not slow down it would hit where it was aimed in spite of the wind.

Saying "provided the shooter does his part" ignores the fact that the shooter rarely does. Even defining that phrase is difficult. Most would say it has to do with bench technique. Reading the wind is far more important in my opinion but I rarely see people at the range with wind flags unless they are benchrest competitors.

The topic of wind drift is complex, widely debated, and not actually the topic of this thread so I won't go into it further here, but it is a great topic if someone wanted to start another thread.

[ifldned]

Fred,
There is a excellent article in Wikipedia under "external ballistics". There is a host of factors that effect the flight of a bullet this article list all that I can think of. Good shooting to you..... from a guy that shoots with wind flags....... ifldned

[Fred_C_Dobbs]

...BC is directly connected to performance in wind because wind drift is directly related to the loss of velocity of the projectile. If the bullet did not slow down it would hit where it was aimed in spite of the wind. ....

Completely wrong. The course of an airplane is affected by the wind, even though it's traveling at a uniform velocity. Airplanes and bullets obey the same laws of physics. Even if a bullet did not slow because of drag, it still would be blown about by the wind. Everything that travels slower than the speed of light is blown about by the wind.

Ignoring the role of mass, the frontal aspect of the bullet is what's most important to BC. For wind drift, it's the lateral aspect. It's possible to design a bullet that would have the identical mass and a higher BC yet be more susceptible to wind drift, or vice-versa. BC can be changed without altering wind drift. Wind drift profile can be changed without altering BC. The two are not directly related.

Saying "provided the shooter does his part" ignores the fact that the shooter rarely does....

So what you're saying is that the less skilled shooter wishes this weren't so.

Fred,
There is a excellent article in Wikipedia under "external ballistics". There is a host of factors that effect the flight of a bullet this article list all that I can think of. Good shooting to you..... from a guy that shoots with wind flags....... ifldned

It pales in comparison to Bryan Litz's Applied Ballistics, which I've read a number of times. And thanks for the snub!

[ifldned]

Hi Fred,
I was testing at the range yesterday,windy day, excellent results, plenty of one hole groups.

Fred, go to website,"Handloads.Com", enter all the pertinent information it asks for out to 1000 yards. The only thing we will change is the bullet configuration for .204 caliber. A 32 grain spitzer has a bc of .181. Switch the bullet to a 32 grain boat tail which has a bc of .215 and check the effects of a 10mph wind on bullet impact at various intervals out to a 1000 yards,not only is the bullet drift significantly different but also notice the bullet drop. I hope we are beginning to understand each other.
ifldned

[rayfromtx]

Fred-
My understanding of this subject came from discussions with Bryan over at benchrest central. The bullet turns into the relative wind as soon as it leaves the barrel. In a right to left condition that means it turns slightly toward the right. If it didn't slow down, it would crab straight toward it's aim point, just as a plane crabs towards it's destination. If it accelerated, it would impact upwind of it's aim point. This is not to say that airplane flight is the same as the flight of a spinning projectile.

I could, of course be mistaken in my rudimentary understanding of external ballistics. My beliefs on the matter were informed by Bryan Litz and he is quite good at explaining his expertise to the lay person. That doesn't mean that my brain is adequate to the task of grasping the concepts. If I'm wrong about this, then I guess my understanding of gyroscopic precession is suspect as well.

Right or wrong, I will continue to respect the capacity of higher bc projectiles to overcome the effects of wind since my grasp of reading the wind is even poorer than my understanding of physics. I will say; however, that skippy wishes I didn't do my part quite as often as I do.

Good day to all. Central Texas is glorious today and I've got planting to do. Cheers

[Jim White]

BC per se has no effect on accuracy.

Fred,

I think you're right. Just because a bullet can shoot flatter and buck the wind better that, in and of itself (per se) will not make a more accurate round. Sure it helps for longer distances but only if the right combination(s) are acheived (load, barrel charactics etc...). Of course the biggest variable of all, the shooter, has to his/her job too (otherwise how do you know its an accurate load?).

As far as the original post goes, I've found that some loads that test well up close do worse than some others that did well at longer distances 500/600 yds. Also, seen it reversed too. The same goes for CHRONO loads. Loads with better #'s looked worse down range on paper.

HTH,