sighting in at 25 yards

probably a silly question, but i've been told several different things....
when you sight in a rifle at 25 yards should you be an inch high, low, or bullseye to be accurate at 100 yards? just trying to get the facts.
Thanks

You need to zero about 1" low at 25 to be close at 100. No matter what, if you want a 100 yard zero shoot the rifle at 100 once you're done at 25.

A lot of were the bullet should strike at 25 yards is dependent on the height of the scope above the bore and trajectory of the cartridge. Using Hornady Ballistics Calculator at 1.5 inches above the bore my 7mm is .6 inches low at 25, at 2 inches above bore it's 1 inch low, when zeroed at 100.

Yup..what I did today

Just so happens my 308 has the same DOPE at 25 yards that it has at 300. MIne would be 4 inches low at 25 yards if I used my 100yd zero

7 yard DOPE is the same as 875 yard.

Yes I have had to shoot that....

I have always thought that the bullet should hit higher at 25 yards than at 100 because in the rise of the bullet as it leaves the muzzle of the gun? Is this not correct? I am shooting about an inch high at 50 yards and right on at 100. Can someone explain why you should be an inch low at 25 yards please? I need to go back to the range and finish sighting in one of my rifles that I had to get a new ejector pin put in. They took the scope off to fix it, and now I have it zeroed back in L/R...but left it at 3" high right before I ran out of daylight at the range. Should I really be 1" low? Would appreciate all advice. I have access to a 25, 50, 100, and 200 range. How high/low should a 30.06 be using 165 grain and 180 grain bullets? I know to zero in with what you will hunt with, just seeing which shoots better in the back-up gun.

Remember your sight line is above the bore so that in order to hit the target a bullet has to cross the sight line twice because it's constantly dropping. At different zeros the first crossing point varies, when it's beyond 25 yards shots at 25 yards will be low, when it's before 25 yards shots will be high. Click on the ballistic calculator link and play with it using the published velocities for the loads your using. That should put you into the ballpark then you can check the results on the range.

Bullets do not rise. Zeroing causes you to elevate the front of the rifle so that the bullet impacts in the same place as where your reticle is. Never a rise in flight though, you're compensating for the fall and the sight offset.

Come all the way back to the muzzle. If you can focus your scope down and see a 1" dot. Where would your bullet impact? Well below what the scope is seeing, due to sight off-set. Same holds true at 25 yards. What you see in the scope is above where the bullet will impact.

Soooooo many people think that a bullet rises and then falls when it leaves the barrel. And so many people cant't figure out why they miss close range shots. You need to practice your shots!

Yessir. I've heard men that have been shooting for decades say that.

How would it be a predictable amount of rise?

a bullet has to cross the sight line twice because it's constantly dropping. I didn't say that a the muzzle is angled slightly up, which I should have, but I never said a bullet rises

No one was talking about you. BigPig was reffering to the O.P. You clearly know how all this works.

my favorite is a 50 yard zero with most rifles

use this as a guide, will help you decide what is best, approximately, for your hunting situations

truth!