Sighting in a scope high powered rifle

[Cee Zee]

Apparently it's only an issue with high magnification or the longer distances you'd commonly use those scopes for.

It actually makes a difference at shorter distances too but again that only really matters if you're talking about a difference of a quarter to half an inch at 50 yards. But the OP asked about a scope on a high powered rifle. He's sighting in at 200 yards which generally means they are planning on shooting farther. They sight in at 200 to allow for some drop to occur to hit their POA. It gives them more holdover. If they were shooting at 100 yards they would adjust the scope to 100 yards because you don't see much bullet drop on most high powered rifles at that distance. He also mentioned using a 10X scope. And parallax does exist on smaller power scopes, it just isn't a big problem but again that is more of a hunting rule than a target shooting rule. If you miss by half an inch when hunting it doesn't matter one bit usually. It's only in target shooting that it matters.

Anyway you have a guy shooting at least 200 yards and using a 10X scope. Both of those are covered by that 9X rule you mentioned. Generally anything out to 100 yards is not considered to be plagued by problems with parallax and the same goes for scopes 9X and less powerful. Again the shooter is shooting more than 100 yards and using a scope more than 9X. Parallax will matter. It might make the difference in a heart shot at 200 yards. You can probably still get a kill but you have to add in your own shooting ability. If your aim is off by two inches and parallax causes you to be off another 3 inches you may have a deer that runs for miles before stopping to rest. It could take off running again if it hears you following it's blood trail. And if your shot was at 300 yards you could miss completely.

Scopes without AO can work very well but you have to learn to use the same cheek weld every time. And that means different people will either have to learn to hold the rifle a specific way (which they probably have not practiced ever) or they will need to adjust the scope for their grip (a much better idea).

With a good rifle and a good scope 300 yards on a deer shouldn't be that hard especially if you have AO on your scope. But not having the right cheek weld on a rifle not adjusted for your hold is just asking to miss completely. Actually 400 yards is doable for decent shooters. But as the distance increases the problems associated with not having a scope adjusted for your hold and your cheek weld get magnified.

I wouldn't think of taking a 400 yard shot with a rifle not adjusted by me to suit my hold and my cheek weld. I probably wouldn't shoot an animal at that distance anyway because too many things can go wrong depending n the caliber of rilfe I was using. I have a 30.06 that would get out that far and have enough energy to kill a deer but it isn't the most accurate rifle I own. It's a decent rifle. I just don't want to maim a deer instead of killing it. And if I wouldn't do it with my own rifle adjusted for my grip then I certainly wouldn't do it with a rifle adjusted for someone else. At 300 yards I wouldn't have a problem using my rifle but no way would I use a borrowed rifle without adjusting the scope first. You clearly need to practice first anyway. You can't just go hunting with any old rifle anyway. I like my 110 but it's not nearly as accurate as my 12 LRPV. But that rifle is a .223 so again I wouldn't shoot a deer with it at 400 yards or likely even 300 yards. Now varmints are another matter completely.

 

[Hangingrock]

After observing shooters at sight in days at three different Sportsmen's Clubs over a period of years the malady of wondering zero from year to year is the shooter and not the optics. I would ask shooters "what's the last thing you saw before closing your eyes". Yes there can be hardware problems optics, rifle, and ammunition but I tend to believe its more of a problematic individual shooter issue. So its within reason that different individuals of differing abilities would shoot a rifle to differing POA.

 

[krimmie]

To add to gamestalker's question, just how much of a difference would the POI be between shooters? I know there are a lot of variables, but assuming the gun is sighted in with a steady rest/sled, I can't imagine too much of a difference, esp. for hunting.

I was one of four sons, and all the rifles were "dads", but we zeroed them each year...during the season we switched back and forth between rifles, so neither of used the same gun all season. Point is, the guns shot well for each of us. I must add that it was rare to get a shot at deer or hog over 150 yards where we hunted,so perhaps increased yardage would yield differnt results.

When I have used a rifle that was not mine, I had to adjust my hold on the rifle so my eye was centered behind the lens.

 

[Cee Zee]

just how much of a difference would the POI be between shooters

Impossible to guess how much. It depends on where each shooter keeps their eyes.

 

[sage5907]

Some people think that if they go to the range and slump down over a shooting bench with a solid rest to sight in a rifle that the point of impact will be the same as when they shoot prone or from a more erect shooting position from a different type of rest. The same applies to multiple users of the same rifle even from the same shooting position. This is not always true because of a change in the cant of the rifle, the position of the eye in relation to the scope, and change in the way the trigger is pulled. As a hunter I always sight in my rifle using the exact same position as I use in the field, and the longer the shooting distance the more critical this becomes. That way I never get a surprise.

 

[taliv]

if your rifle action/barrel are properly isolated from the stock/bipod/sling/etc it shouldn't make a difference. PRS shooters shoot from every position you can imagine and it would be unusual to have a POI shift from positions.

However, it can happen and i've experienced it once. i shot my HP service rifle for years using the same dope for 200 yard line both standing and sitting, but suddenly, that changed and i was about 2 minutes different between positions and i never figured out why. but it was consistent enough that i could still shoot accurately that way.