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acemisser
09-29-2012, 06:05 AM
Is it true that if you shoot a 1/2 inch group at say 125 yards that it
will be 1 inch at 250? How do they,whoever they are figure this out..?

I could never understand how they got this figure in the first place...

Thats like saying if you shoot a 1 inch group at 100 yards it will be 10
inch at a 1000 yards..Come off it...No way....Or am I missing the boat
on this all together...

fgw_in_fla
09-29-2012, 06:30 AM
I don't know about anyone else but when I shoot 1" at 100yds, it's usually 1.5" to 1.75" at 200yds.

I've had bullets that shot 1"+ at 100yds & .5" to .75" at 200..... I never did figure that out.

Getting into all the technical stuff about long range shooting always seemed kinda confusing to me. As long as I'm keeping 'em tight regardless of the distance, I'm doing what I like.

Frank in Fla

fgw_in_fla
09-29-2012, 06:35 AM
I think you're just trying to confuse me with the facts.....

There'll be none of that arond here.

Stay well....

Frank in Fla

rjtfroggy
09-29-2012, 06:39 AM
Think of MOA as minutes on a clock for every minute the angle increases by one (1).
There is a video on youtube that explains it, done by a sniper instructor, you may be able to find it on the gun broker site that is where I saw it.
Sorry I can't look it up right now I'm about to leave for a match.

lal357
09-29-2012, 09:13 AM
depends on the bullet my 6.5 vld's shoot alittle better the farther i go out i think it needs alittle more to stabilize them

earl39
09-29-2012, 10:52 AM
Is it true that if you shoot a 1/2 inch group at say 125 yards that it
will be 1 inch at 250?

No it is not true most of the time.



How do they,whoever they are figure this out..?...

It is figured using simple math.




Thats like saying if you shoot a 1 inch group at 100 yards it will be 10
inch at a 1000 yards..Come off it...No way....Or am I missing the boat
on this all together...

That is exactly what they are saying altho they are missing the boat with actuality.

acemisser
09-29-2012, 10:55 AM
so then what is the real deal about it then..? I need layman terms..My itty bitty brain
will burn out trying to figure too much out..

Admin
09-29-2012, 11:11 AM
Simple....

http://riflestocks.tripod.com/moa.jpg

1 MOA = 1" @ 100 yards (well, technically it's 1.0472" but common acceptance is 1")
or 2" @ 200 yards
or 3" @ 300 yards
or 4" @ 400 yards
...see where this is going?

So if your rifle shoots a .75" group at 100 yards, that's 3/4 MOA. Theoretically, the rifle should be capable of maintaining that same 3/4 MOA at any reasonable distance for the cartridge/bullet combination. If we're talking 1,000 yards it would be a 7.5" group. Of course this assumes that the shooter remains consistent with his part of the accuracy equation as the distance increases and is adeptly skilled at reading and adjusting for the conditions.

acemisser
09-29-2012, 12:02 PM
Jim-Thanks,thats makes alot more sense to me that the other stuff does..John

fgw_in_fla
09-29-2012, 01:27 PM
I knew that....

jon8777
09-29-2012, 09:43 PM
lal357-

I had a .223 that would shot a progressively tighter moa group from 50 yards to about 200 yards and after 225 the group would expand in moa group size as you would predict. I never had a gun do this, after reading I found this bullet "goes to sleep". Very interesting reading on this topic.

WuzYoungOnceToo
09-30-2012, 02:10 AM
lal357-

I had a .223 that would shot a progressively tighter moa group from 50 yards to about 200 yards and after 225 the group would expand in moa group size as you would predict. I never had a gun do this, after reading I found this bullet "goes to sleep". Very interesting reading on this topic.



What exactly does "goes to sleep" mean? That the laws of physics cease to apply to it? Because that's what it sounds like you're describing.

M.O.A.
09-30-2012, 02:24 AM
It stabilizes later as bolt tail bullets sometimes do it has to do with the gases exiting around the end of the bolt tail of the bullet.

WuzYoungOnceToo
09-30-2012, 02:42 AM
Late stabilization cannot cause a projectile that has deviated from an average ballistic trajectory at a given distance to suddenly and magically change trajectories such that it consistently heads back toward the POA and results in reduced deviation at a further distance.

kevin_stevens
09-30-2012, 03:02 AM
Late stabilization cannot cause a projectile that has deviated from an average ballistic trajectory at a given distance to suddenly and magically change trajectories such that it consistently heads back toward the POA and results in reduced deviation at a further distance.

+1

You people who are saying that you shoot smaller groups at a longer distance are talking about something YOU are doing, not the gun and not the bullets. Your group size is a product of an ANGULAR dispersion from the muzzle of the gun. Saying you are 2 MOA off at 100 yards and 1 MOA off at 200 is to say that the bullets not only deflect in flight, but do so consistently in a manner that corrects their flight toward your desired point of aim.

You need to stop and think about this for a minute. These aren't missiles you are firing, they are bullets. Now, there's two possibilities if your groups are tighter at longer distance than shorter: one, you, the variable in the equation, are doing something differently; or two, you have magic bullets.

Your call.

KeS

To the OP - yes, if you are shooting 1" groups at 100 yards they would diverge to 10" groups at 1000 yards. The reason that doesn't happen in real life is that on the longer shots, there is more time for wind, bullet irregularities, etc. to manifest themselves. Offsetting that, a lot of people are poor at measuring group size, and there's less error in that measurement at greater distances.

kevin_stevens
09-30-2012, 03:15 AM
1 MOA = 1" @ 100 yards (well, technically it's 1.0472" but common acceptance is 1")

Note that this is just a coincidence of the English measuring system, there's nothing inherent about it. Geometrically, there are 360 degrees to a circle, and 60 minutes to a degree - so 21,600 MOA to a circle. It just so happens that there are 36 inches in a yard, and using the formula 2 x pi x R to calculate the circumference of a circle, you get 2 x 3.14 x 3600 inches, or 22,608 inches. So a circle = 21,600 minutes and 22,608 inches, or the 1.05 in/MOA Jim gave you. At 200 yds you still have 21,600 MOA, but now you have twice the radius, so twice the in/MOA - 2.1. And so on.

If you're working in another measurement system, you won't get the nice 1:1 correlation, but the MOA will always be constant and the group size will always increase proportionately to the distance.

KeS

WuzYoungOnceToo
09-30-2012, 03:46 AM
But the strength of the cell phone signal when you're calling home to brag about your magical better-at-200-yds-than-at-100-yds groups decreases proportionate to the square of your distance from the nearest cell tower, and.....

Ah, I'm just screwin' with ya'. :cool:

acemisser
09-30-2012, 08:25 AM
Man looks like we hit the jackpot on this question...Now all one needs to do is be sure all conditions are the same from A TO B when squeezing the trigger...

Jamie
09-30-2012, 09:04 AM
As a bullet leaves a barrel the rotation of it will cause it to oscilate slightly. It is not uncommon at all for MOA to change because of this. This is also the reason that the load that produces the smallest group at 100 yards does not always produce the smallest group at 500 yards.

Now I am not talking about shooting 3" group at 100 and then shooting a 1/2" at 500. I have owned one that would shoot the same size group at 200 yards as it did at 100 yards.

skypilot
09-30-2012, 09:23 AM
Jim and Kevin both nailed it. Jim on the firearm capability and Kevin on the YOU factor. Even if the firearm is a .3 MOA @ 100yds., in the real world past a few hundred yards, environmentals affect POI more than anything.
If the firearm shoots to a POA consistently at incremental distances AND you are "on" the environmentals(zero environment vs current environment, wind, density altitude,etc.) groups are smaller.