What would cause this situation when sighting in a rifle?

[jrdolall]

Yesterday a friend and I sighted in a new rifle for another friend, sort of a spur of the moment thing. He was working, knew we were headed out and asked us to sight in his new gun. My buddy got the gun shooting pretty good at 100 yards. I took the gun and fired three times and every one of my shots were low by 2" and right slightly. He took the gun back and fired three shots that were all POA. We were resting on the hood of a pickup.

Is it how we hold the gun and align the scope? The gun was a brand new 270 but I won't mention the name of the gun or scope because that shouldn't be relevant. It was a rather cheap combo package so I wouldn't necessarily expect perfection anyway. The box of shells he gave us were Winchester, I think 135 grain but that really shouldn't matter either since his shots grouped ok and mine grouped ok. We weren't looking to shoot a gnat but just get it close so the guy could take it this weekend and it would already be "sighted in".

 

[MCMXI]

Is it how we hold the gun and align the scope?

Absolutely. A rifle zeroed for you won't necessarily be zeroed for someone else. Cheek weld, parallax, trigger control, forend pressure, recoil management etc. all effect the zero. I had the same experience a couple of weeks ago with a .270 Win rifle I procured for a friend. I had it shooting great at 100 yards for me but it shot 1.5" right for her. I had to dial a correction into the scope and she learned what it means to zero a rifle. She nailed a whitetail buck in the heart at 150 yards a few days later so she had a good zero.

 

[allaroundhunter]

Were y'all resting it on anything?

 

[HOOfan_1]

parallax possibly

 

[illinoisburt]

Absolutely. A rifle zeroed for you won't necessarily be zeroed for someone else. Cheek weld, parallax, trigger control, forend pressure, recoil management etc. all effect the zero.

Yup. All about how you hold the gun. Slight canting will very easily cause this issue.

 

[desidog]

One of you is a Lefty and the other a Righty?

 

[jrdolall]

We were resting the gun on the hood of a truck and both are right handed. I think my suspicions are confirmed but just wanted to get some input. I plan to take a site vise this weekend and make sure the OWNER gets it sighted in. We should be able to do that with just a few shots since we know it's in the vicinity.
I have sighted in rifles for people in the past but never had it where two people shot the gun.

 

[chicharrones]

Absolutely. A rifle zeroed for you won't necessarily be zeroed for someone else. Cheek weld, parallax, trigger control, forend pressure, recoil management etc. all effect the zero.

I've had the same experience as 1858. I almost always go shooting with another person and we trade guns often. Our zeros are usually off from one another.

 

[chicharrones]

What's a "Site Vise", a rifle rest of some sort? In my experience, a rifle rest can can have a different zero than a shooter putting the gun on a bag or holding it off a rest. I figure it from the aforementioned recoil management as I can notice a muzzle move differently from a locked down rifle rest versus the human hold.

 

[carbine85]

It's probably best for your friend to sight it in to his shooting style. If it's a hunting rifle it has to be tweeked to his hold.

 

[JDGray]

Always sight in your own rifle, and do it how your going to use it.

 

[22250Rem]

Sounds like you and your friend got it sighted in good enough that it should be on the paper when the owner does the final sight-in. Different people can have different zero's but that stuff has already been mentioned. So now the owner should be able to do his final sight-in and make the final fine tuning which should only consist of some small, minor adjustments. Make sure he uses the same ammo that you did and he should be good to go.

 

[ZGunner]

Yup, different people aim differently and POI will change between shooters.

My wife and I are lucky enough to shoot the exact same. I mean to the millimeter! This is yet another reason I know we're meant for each other.

 

[sage5907]

The situation you have just described is why hunters go to the rifle range every year just before deer season to make sure their rifle is still sighted in. They shoot the rifle and it groups in a different place than it did last year and they change the zero thinking they have solved the problem. The truth is that they are holding the rifle differently, canting the rifle differently, using a different rest or a different shooting position. Then next year they adjust the zero again. Not a clue about what is going on. In reality, if the shooter had left the zero as it was the rifle would still shooting in the same place as it did last year.