Sighting in a scope high powered rifle

[gamestalker]

I am in an on going argument with my Son as to whether it matters who sights a rifle in. In other words, if I sighted his rifle in at 200 yds., will it shoot the same POI with him behind it at 200 yds.?

We are talking about a bone stock run of the mil Leupold 3.5x10x40 VX-III. I am saying that it will shoot the same POI regardless of who is behind it. His opinion is quite diferent, and he says it absolutely won't shoot the same POI, and in fact will have a significantly different POI.

The reason for this debate, as it were, is that he doesn't have the time to sight his rifle in prior to his up coming hunt, to which I have offered to do for him.

What say the experts on this topic?

GS

 

[ColtPythonElite]

I say it will.

 

[readyeddy]

same

 

[Revoliver]

Your son is absolutely correct.

 

[youngsait]

It's believed that the man behind the scope determines the POI. But not sure.

 

[jmr40]

There could be slight differences in POI between users. Might not be any differences, it just depends on how the different shooters mount the gun and look through the scope. For deer hunting, not enough to use as an excuse if someone misses though.

 

[ngnrd]

The rifle won't shoot any different. The person behind the trigger will. How firmly the rifle is held to the shoulder, where and how the fore end is held, breath control, trigger control... These things all contribute to changes in overall accuracy from one shooter to the next. But, unless the both shooters are consistent with the differences, and those differences are substantial, there shouldn't be much change in POI.

If you want to take out as much human error as possible for the sake of sighting in, shoot from a steady bench, with the rifle solidly supported with sandbags or a lead sled type rest. When you know the sights are aligned with the path of the bullet, the primary shooter should only need a few shots to confirm that their shooting mechanics provide the POI they're expecting.

 

[hardluk1]

I hunted with a friend for close to 30 years. He was the best natural shooter I ever saw but could not sit at the bench and zero his rifle or check it ever year before the season started so I did it. It always worked as he needed it to and at some very long distances.

 

[mavracer]

How you hold the gun can make a difference in POA. If you shoot prone with a sling you will usually shoot a bit lower than shooting off a bench or bi pod, because you wont let the muzzle climb as much.

So yes two different guys would be more than capable of shifting impact.

 

[akolleth]

It definitely will change, although how much is the question. My father in law and I often shoot together at the range. He and I both have POI changes when we shoot each others rifles, even moments after the other has sighted it in perfectly. I have noticed that whenever I shoot his rifles it always ends up low and left, but he can shoot the same rifle and it will be perfectly centered for him. Like everyone is saying has to do with the way we hold the rifle, cheek welds, etc...

 

[Art Eatman]

There's always the possibility of some amount of parallax or canting which can vary from person to person as to how they hold a rifle.

 

[HexHead]

The mechanics of how you hold and operate the rifle will effect the POI, but once the scope is aligned with the bore of the barrel they are on the same plane. If you sight in his rifle from a solid bench rest position, or with a Lead Sled as mentioned above, and he misses with it, it's him. It's the Indian, not the arrow.

 

[HexHead]

It definitely will change, although how much is the question. My father in law and I often shoot together at the range. He and I both have POI changes when we shoot each others rifles, even moments after the other has sighted it in perfectly. I have noticed that whenever I shoot his rifles it always ends up low and left, but he can shoot the same rifle and it will be perfectly centered for him. Like everyone is saying has to do with the way we hold the rifle, cheek welds, etc...

Sounds like he's just a better shot, and you're jerking the trigger. Low and left is a classic symptom of that.

 

[john843]

I've had this same discussion with my BIL. I upgraded a rifle for him earlier this year and after mounting a new scope, sighted it for him. I shoot left-handed and he's right-handed. He's killed 2 pretty good bucks with it so far this year, so we know it's at least at minute- of- whitetail, but have seriously wondered about the RH vs LH aspect. Any idea?

 

[RussellC]

Anyone who has aligned a Scope in the business would tend to say no difference, for the most part. Years ago I worked at JC penneys way back when they carried guns and I performed bore sighting for all sorts of folks, most of them were very impressed. I would always tell them that it would take a little adjustment to be spot on, but this would get them close enough to see where it was hitting at least. Now if your shooting is different enough, or mechanics of your shooting stance is signifigently different, it could be a little off, but the scope is aligned to the bore, not the shooter! Of course there is also room for error in the equipment and one using it.

Russellc

 

[GarySTL]

Don't forget scope parallax. If it's not adjusted out a slight difference in cheek weld could result in a different point of impact, right?

 

[RussellC]

I've had this same discussion with my BIL. I upgraded a rifle for him earlier this year and after mounting a new scope, sighted it for him. I shoot left-handed and he's right-handed. He's killed 2 pretty good bucks with it so far this year, so we know it's at least at minute- of- whitetail, but have seriously wondered about the RH vs LH aspect. Any idea?

Definitely a variable, but again, done correctly, the scope is aligned to the bore...I shoot my AR15 with iron sights both right and left handed and I am just as bad either way!

Russellc

 

[RussellC]

Don't forget scope parallax. If it's not adjusted out a slight difference in cheek weld could result in a different point of impact, right?

Never dealt back then with scopes that had adjustable parallax. We just carried your basic Bushnell stuff. Back then, I only understood parallax to be a problem if you put a high powered rifle scope on a .22. although I mounted many 4x32 rifle scopes to .22 rifles with the owners claiming they hit like donkey kong, but thays just 50 yard plinking, not serious long distance shooting. I thought parallax was built into the scope, didnt know it was adjustable, please school me! I havent touched a scope in over 25 years!

Russellc

 

[RussellC]

The mechanics of how you hold and operate the rifle will effect the POI, but once the scope is aligned with the bore of the barrel they are on the same plane. If you sight in his rifle from a solid bench rest position, or with a Lead Sled as mentioned above, and he misses with it, it's him. It's the Indian, not the arrow.

Agree completely. Your analogy hits the nail on the head.

russellc

 

[RussellC]

Sounds like he's just a better shot, and you're jerking the trigger. Low and left is a classic symptom of that.

Correct again, Especially with handguns which of course have a much shorter barrel, and while rifles have longer barrels, the shots can cover a much longer distance. Low and left is classic sign of trigger work needing help, I guess if you are consistent enough with the low and left, someone may have adjusted the scope to compensate for it. Then you shoot a gun that isnt set like that, you hit low and left...assuming you are right handed anyway.

russellc

 

[GarySTL]

Parallax is caused when the reticle and one of the intermediate images are not in the same plane. This causes the reticle to appear to move on the target as your eye is shifted in relation to the scopes rear lens.
Many newer scopes have a parallax adjustment knob, often marked in yardage. 50 to 500 is not unusual. If the scope doesn't have an adjustment, I've been told that sometimes adjustment may be made at the objective lens, but I've never seen it done myself.
Parallax can cause misses at longer ranges if your eye is not in exactly the same position as when you sighted in.

 

[John3921]

I have always thought it made some difference - because of grip, check weld, etc. But not a huge difference - otherwise shooting offhand vs shooting prone, vs shooting from a rest would all make a similar difference.

This year I loaned my .300 win to my son-in-law. I sighted it in using fresh newly loaded 200 gr nosler partitions. I loaded plenty so he would have no problems dialing it in for himself. He got busy with work and never had a chance to mess with it. It didn't seem to matter much, he dropped a 5 pt bull elk with a spine shot just behind the ears. DRT.

 

[Cee Zee]

I "know" it makes a difference. If your scope isn't adjusted perfectly for parallax and slight difference in the location of the shooter's eye will affect the POI. It can make you miss an inch at 50 yards. Tha's the extreme of course but parallax is one of the most important things you can do to make for a consistent set of groups. It's helped me win 12 out of the last 15 contests I shot in. I was amazed at how much difference it made when I finally got my parallax perfectly adjusted for 50 yard bench rest competitions with rimfires. My groups went from an average of .75"-1" down to .25" - .5" and my scores went way up. I even marked the AO adjustment on my Weaver T-36 so I'd know exactly where to set my scope (or close to it) when I wanted to do 50 yard BR contests. Of course it won't be the same for different rifles or even if your scope gets re-adjusted forward or backward. That part doesn't matter a lot but every little bit matters in BR shooting.

In some situations where parallax doesn't matter that much it doesn't matter if a different person is shooting the rifle or at least not much. But I work hard to get the same cheek weld even though parallax pretty much counter acts that problem. But I won't to take every variable out of the equation that I can.

Again maybe some won't notice the difference if they aren't as picky about absolute accuracy as a BR shooter is. But it does matter for sure. Every little difference in the location of the shooter's eye changes where that scope points if you don't have the parallax perfect. And if you are shooting unknown distances the cheek weld still plays a major role in keeping your bullets on target. So my advice would be to have the shooter adjust the scope and make sure the cheek weld stays the same on every shot. It's easier said than done of course but the closer you get to the same location for your eye the more accurate your shooting will be.

Parallax can cause misses at longer ranges if your eye is not in exactly the same position as when you sighted in.

I don't think it would cause actual "misses" at shorter distances but it does matter. If you measure a good group in tenths or even hundredths of an inch it will matter. If you're just trying to kill a squirrel at 50 yards it won't matter that much to you. But if you want to win the BR competition at the local gun range it certainly matters.

 

[redneck2]

I see guys that post here saying parallax isn't important. It is, particularly for small groups as noted. I always try to use a 6.5x20x40 AO for load development. Back about forty years ago when I got my first 22-250, I had a fixed 10x. Parallax was so bad at longer range that I'd move my head back and forth and try to shoot for the middle. It would move entirely off a groundhog at 300 yards.

 

[HexHead]

I have two scopes with Adjustable Objectives for parallax, both VX-2 4-12x40s. My VX-3 3.5-10 didn't even have it as an option. My understanding is that it's not necessary unless your scope is over 10x. I don't recall seeing it on scopes 10x or under.

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