Hello All,

Here is my problem and I hope you guys can help. I have a .270 Win and I am shooting Winchester 150 grain Nosler Partitions. Anyways, I shoot a fairly good grouping at 100 yards and the group is about 3 inches above the bullseye. The problem is that at 200 yards my grouping is about 5-7 inches above the bullseye. Can someone explain how this is happening. I cannot figure it out. I thought that if the grouping was at about 3 inches high at 100 yards it would be close to dead on at 200 yards. The other question is about adjusting the scope. On the MOA dial that says up and down. If I move it say 4 clicks in the direction the scope says down, does that mean I am moving my shot DOWN 1 inch or UP 1 inch?

Any help would be great

The height of scope centerline above the bore centerline will determine the height of bullet flight at the varying distances.

Most scopes are considered to be mounted with 1.5" between the two centerlines. If you have a large objective lens scope, or high mounts for "see through" effect, then your scope will be above the normal mounting distance and the bullets will impact higher at 200 yds with a 100 yd sight-in than those mounted at normal heights.

Since you're aware of the excess point or impact (POI) at 200 yds, you can compensate with a lower 100 yd sight-in. You should shoot at all ranges out to the maximum comtemplated to assure just where each grouping will be.

Most scopes today have 1/4" adjustments. This means one click will equal 1/4" movement at 100 yds. The "Up"/"Down" and "L"/"R" arrows on the knobs mean that is the direction the POI will be moved on the target with adjustment, not the way the reticle will move.

Without confusing the issue too much, if you are able to clamp the scope/rifle in a solid, unmoving position and moved the windage adjustment knob in the direction of the "L" (meaning Left) arrow while looking through the scope, you would notice the reticle move right. This pulls your muzzle to the left which is the direction you want the shots to go.

Same applies for the "U" and "D". The reticle goes in reverse of the direction indicated on the knob.

The easy way to remember is that the adjustments are for moving the group to the reticle. That is not what you are really doing of course, but if your group is to the right and high, you put in the adjustment down and left, as if you were moving the group.

That old rule of thumb; 3" high at 100 yards puts you dead on at 200" is close for a slow load in a .308, and with a round nosed bullet. Change to your .270 load, add high altitude, high temperature and a high scope, and it's not even close. You're zeroed for 300 yards or a bit more. Run your numbers through the Ballistics Calculator and see what you get.
http://www.beartoothbullets.com/rescources/calculators/balistics/index.htm

Bye
Jack

The situation is this,

My scope is mounted 1.5 inches off the barrel. It has been in the high 90 degree range and the humidty is around 95%. I live in minnesota so our altitude is not high. Anyways, I guess I could be sighted in for 300 yard, which somehow makes sense. If I draw the curve of a bullet through the straight line of a scope and if you are right and I am sighted in at 300 yards, then the bullets initial cross through of my line in the scope would be just before 100 yards, right? Anyways, I gues the only thing to do is adjust the scope way down so I get the second cross through of the scope at 100 yards, RIGHT?

The first crossover is at 31-33 yards for a 200 yard zero. Sight-in 1.6" high at 100 yards. That's as close as I can come without shooting your rifle myself.

Bye
Jack

Thanks,

I will try that.