Confused by POI

[AllenOne1]

Shot a match today that is a "modified" benchrest format. You can shoot at a steel sighter target as many times as you want and you have to put 5 shots on paper for score all in a 5 minute window. I shoot it as a tactical shooter with a bipod. We shoot 4 rounds all at 600 yards.

The issue I had today was when shooting the sighter plate the shots appeared to be right on the money so I went to the paper and shot my 5 shots for score then went back to the sighter to confirm and again it appeared to be right on. When I got the target back however the 5 shots were off center by roughly 4". The group was very good, for me just off center.

Could this be optical when changing from the steel to paper or is it most likely just a wind change that I didn't pickup? Any ideas? This is my first year shooting this and I'm just trying to figure it out and get better.

Thanks,

 

[OmegaRed]

Shot a match today that is a "modified" benchrest format. You can shoot at a steel sighter target as many times as you want and you have to put 5 shots on paper for score all in a 5 minute window. I shoot it as a tactical shooter with a bipod. We shoot 4 rounds all at 600 yards.

The issue I had today was when shooting the sighter plate the shots appeared to be right on the money so I went to the paper and shot my 5 shots for score then went back to the sighter to confirm and again it appeared to be right on. When I got the target back however the 5 shots were off center by roughly 4". The group was very good, for me just off center.

Could this be optical when changing from the steel to paper or is it most likely just a wind change that I didn't pickup? Any ideas? This is my first year shooting this and I'm just trying to figure it out and get better.

Thanks,

Lots of potential things. My guess if I had only one would be torque on the bipod.

 

[rardoin]

Wind. Period! Run a calculation based on your load and the best guess of the extremes of the wind (angle and velocity both) and see if it fits what you saw on paper.

 

[shoot4fun]

Where is the sighter plate in relation to the paper target?
That will change where you hit on paper.
Our sighter steel is under the record target and even off a rest there is a difference in POI.

 

[jackieschmidt]

In years past, we have been shooting 600 yard “fly shoots” in Huntsville.

The target frame has a sighter plate about 3 feet below the record target.

Since the range is dead flat, when you shoot at the sighter, you are shooting slightly downhill. The record, slightly uphill.

The difference in the two is about 2 to 3 inches high on the record if you are dead on the sighter.

 

[dolek]

Wind. Period! Run a calculation based on your load and the best guess of the extremes of the wind (angle and velocity both) and see if it fits what you saw on paper.

Not true ,many other factors involved....gravity,geometry,elevation,sighter/record target positioning,to name a few.

 

[johara1]

So what way were the shots on paper off from the plate? if it were left or right I would bet conditions changed.Is the plate the same distance as the the target?....jim

 

[AllenOne1]

Where is the sighter plate in relation to the paper target?
That will change where you hit on paper.
Our sighter steel is under the record target and even off a rest there is a difference in POI.

The official sighter plate is under the record target so 3 feet low. I felt this could be throwing me off so I moved to a large steel plate which was about 3-4 feet to the right and maybe a foot or less lower.

 

[AllenOne1]

So what way were the shots on paper off from the plate? if it were left or right I would bet conditions changed.Is the plate the same distance as the the target?....jim

The plate is at the same distance as the paper target. The record shots are off center 3.5" right and 2" low. The group was 2.023, best group of the day, worst score.

Looking at all 4 targets I'm thinking more and more that I had conditions changing that I'm not adjusting for.

 

[JFrank]

The plate is at the same distance as the paper target. The record shots are off center 3.5" right and 2" low. The group was 2.023, best group of the day, worst score.

Looking at all 4 targets I'm thinking more and more that I had conditions changing that I'm not adjusting for.

That happens to me more than anybody I’ve ever seen.

 

[243BR]

+ 1 for a change in conditions / wind, especially if you shot your record rounds in a short period of time and then went back to the steel. A 1 mph change in wind speed can move 103 - 108 grain bullets 6mm bullets traveling at 2900 fps 2 + inches (calculations from Applied Ballistics Point Mass Ballistics Solver 3.0).

 

[johara1]

The plate is at the same distance as the paper target. The record shots are off center 3.5" right and 2" low. The group was 2.023, best group of the day, worst score.

Looking at all 4 targets I'm thinking more and more that I had conditions changing that I'm not adjusting for.

I would bet on conditions any kind of range flags or can you use a spotting scope to se the mirage ? you need to shoot under the same condition..... jim

 

[Pawnee Bill]

I have been confused on my POI for the last 50 years of shooting. They never go where they should go.

 

[AllenOne1]

I would bet on conditions any kind of range flags or can you use a spotting scope to se the mirage ? you need to shoot under the same condition..... jim

There were a few wind flags and they were giving very mixed signals at different yardages. I decided I needed to trust what I was seeing on the target and that was likely were the mistake is being made. I need to get some wind flags of my own and practice shooting with them. The mirage could be seen through your rifle scope later in the match but I think it was showing right to left but the shots were going right.

 

[Sundown]

How much wind?...Wind in same direction you were off the target?...How far off the ground is the target?
At our range we would shoot two targets at one sitting, one above the other by 4 1/2'. With a wind from 45 Deg. from behind the berm, the lower target POI would be 4-5" right of the top target. So the berm had an effect on POI.

 

[rardoin]

Not true ,many other factors involved....gravity,geometry,elevation,sighter/record target positioning,to name a few.

Ok

I completely disregarded the difference in gravity on the sighter target ad the record target. Lets not forget the EMF induced by the spin of the copper projectile in proximity to the steel plate which is not present on the paper record target....

 

[DOGCAPPER]

Hell, I thought it was suppose to do that.

 

[AllenOne1]

How much wind?...Wind in same direction you were off the target?...How far off the ground is the target?
At our range we would shoot two targets at one sitting, one above the other by 4 1/2'. With a wind from 45 Deg. from behind the berm, the lower target POI would be 4-5" right of the top target. So the berm had an effect on POI.

Wind at the shooter was almost nothing most of the day, at 300 yards we were estimating the wind to be going from 3 mph left to right to nothing to 4 mph right to left. The flag at the target up on the berm was showing from nothing to a slight left to right. Mirage was going right to left at the ground in front of the target. I was off center to the right on the last target.

The paper target is centered at about 5' off the ground.

 

[JFrank]

I sometimes feel the sunlight on the target/targets to be skewing my perception from one to the other almost like a wrinkle in the paper adds a shadow that I falsely read.

 

[johara1]

There were a few wind flags and they were giving very mixed signals at different yardages. I decided I needed to trust what I was seeing on the target and that was likely were the mistake is being made. I need to get some wind flags of my own and practice shooting with them. The mirage could be seen through your rifle scope later in the match but I think it was showing right to left but the shots were going right.

The mirage you see in the scope is at the target, too late then. a spotting scope you can focus at any yardage and see the mirage there.... jim